Sentence Correction

Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

a)the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.
b) the effects that are the most obvious ones, extremes of temperature, precipitation, and storminess, would be those impacting the most on people.
c) those effects to have the largest impact on people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects.
d) extremes of temperature, precipitation, and storminess, the most obvious effects, that they would have the largest impact on people.
e) extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people.

[spoiler]OA: A[/spoiler]

I am totally baffled with answer choice A.
I read some comments on answer choice A in different forums. Many say that "and those that would have the largest impact on people" part is modifier.
Is it really a modifier? If so ,how is that?
I penned down answer choice C.
Can Experts/GMAT folks help me to understand the correct answer choice?
It will be helpful to me if you can state reasons for eliminating wrong answer choice

I see two problems with C.

those effects to have the largest impact on people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects. -- the usage of 'Those' is not clear here.. Ideally those should be referring to 'extremes of temperatures, precipitation....'

the latter part looks very awkward to me and grammatically incorrect. 'Are what' doesn't even sounds good to my ear

I agree with saketk in his explanation

Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

a)the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.
b) the effects that are the most obvious ones, extremes of temperature, precipitation, and storminess, would be those impacting the most on people.
c) those effects to have the largest impact on people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects.
d) extremes of temperature, precipitation, and storminess, the most obvious effects, that they would have the largest impact on people.
e) extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people.

A looks good

gauravgundal wrote:Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

a)the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.
b) the effects that are the most obvious ones, extremes of temperature, precipitation, and storminess, would be those impacting the most on people.
c) those effects to have the largest impact on people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects.
d) extremes of temperature, precipitation, and storminess, the most obvious effects, that they would have the largest impact on people.
e) extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people.

[spoiler]OA: A[/spoiler]

I am totally baffled with answer choice A.
I read some comments on answer choice A in different forums. Many say that "and those that would have the largest impact on people" part is modifier.
Is it really a modifier? If so ,how is that?
I penned down answer choice C.
Can Experts/GMAT folks help me to understand the correct answer choice?
It will be helpful to me if you can state reasons for eliminating wrong answer choice

This question from New York Times :

https://www.nytimes.com/1995/05/23/scien ... fect.html- 6th paragraph

The phrase - "those that would have the largest impact on people" is not acting as a modifier as the construction refers.
The climatologist indicated :
- that the most obvious effect
- that would have the largest impact on people.
Though the second phrase actually classifying the effect, it is not an modifier as we cannot start a modifying clause with "and". For E.g
I went to Boston,the most beautiful city.
I went to Boston, and the most beautiful city ( wrong )

since your confusion is about C, it has both modifier problem and stylish error ( redundancy), I will try to explain the construction error in C as far as possible.

1)extremes of temperature, precipitation, and storminess are some example that are sighted , so "such as" should be used or else the phrase "extremes of temperature, precipitation, and storminess" seems to modify "the people"
2) " are what are " - redundant
better - those effects to have the largest impact on people such as extremes of temperature, precipitation, and storminess, are what are the most obvious effects (remove the comma and "what are" )

gauravgundal wrote:Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess.

a)the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess. - parallel and Active
b) the effects that are the most obvious ones, extremes of temperature, precipitation, and storminess, would be those impacting the most on people. - PASSIVE
c) those effects to have the largest impacton people, extremes of temperature, precipitation, and storminess, are what are the most obvious effects. - Its not direct!!
d) extremes of temperature, precipitation, and storminess, the most obvious effects, that they would have the largest impact on people. - Not direct
e) extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people. - Changes the meaning

IMO:A

A

You will not make it.
Pavier Simpson
Nice question