Hello Everyone!
Let's take a closer look at this question, one issue at a time, and narrow it down to the correct choice! Before we dive in, here is the original question, with any major differences between each option highlighted in orange:
Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots on the surface of the Sun but have never been sighted on the Sun's poles or equator.
(A) are visible as dark spots on the surface of the Sun but have never been sighted on
(B) are visible as dark spots that never have been sighted on the surface of the Sun
(C) appear on the surface of the Sun as dark spots although never sighted at
(D) appear as dark spots on the surface of the Sun, although never having been sighted at
(E) appear as dark spots on the Sun's surface, which have never been sighted on
After a quick glance over the options, a couple major differences jump out:
1. How they begin: visible as / appear as
2. Verb tense: have been sighted / sighted / having been sighted
It's always a good idea to start with any issue that will eliminate 2-3 options at once. Let's start with #1 on our list because it'll eliminate the most options to get us started!
While it may seem that appear and visible are interchangeable terms, they do mean slightly different things:
Visible = The object already exists, is not moving, and you are able to see it. (The stop sign is visible from a distance of 200 yards.)
Appear = The object is created as you're looking, or it moves into your path of vision. (My dog appears at my feet when he's ready to go for a walk.)
It makes more sense in this context to say that sunspots are visible on the surface of the Sun. They already exist, and they aren't moving into your vision path - they are stationary. The sentence is merely stating that you are able to see them, not that they move around or are created in front of your very eyes.
Therefore, we can eliminate options C, D, and E because they use the more vague "appear," rather than the clearer term "visible."
Now that we have it narrowed down to only 2 options, let's take a closer look at the remaining options:
(A) are visible as dark spots on the surface of the Sun but have never been sighted on
This option is CORRECT! It uses the clear term "visible" to describe sunspots, and it makes logical sense to use "have never been sighted" to refer only to the poles and equator.
(B) are visible as dark spots that never have been sighted on the surface of the Sun
This is INCORRECT because it drastically changes the original meaning of the sentence! The original sentence states that we can see sunspots on the surface of the Sun, with the exception of the poles and equator. This sentence says they have never been sighted on the surface, which isn't true!
There you go - option A is the correct choice! It uses clear terminology and makes logical sense!
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Now, I'm sure you're wondering what would happen if we tackled #2 on the list instead. Here is how we could break down this question based on verb tenses:
(A) are visible as dark spots on the surface of the Sun but have never been sighted on
This is CORRECT because it uses the correct verb tense (present perfect) to show that they weren't found in the past, and haven't been found in the present too.
(B) are visible as dark spots that never have been sighted on the surface of the Sun
While this sentence uses the correct verb tense, the location of the verb is wrong! In this case, it's referring to the surface of the Sun, which doesn't make sense - we CAN see sunspots on the surface! This is INCORRECT because it drastically changes the intended meaning, which is a big no-no on the GMAT!
(C) appear on the surface of the Sun as dark spots although never sighted at
This is INCORRECT because it uses past tense to show that the sunspots were not visible in the past, but says nothing about the present. The original sentence suggests that the sunspots are still not visible on the poles or equator today, so we need to use present perfect tense to show that.
(D) appear as dark spots on the surface of the Sun, although never having been sighted at
This option is INCORRECT for a couple reasons. First, it doesn't make sense to say that sunspots aren't visible AT the poles or equator - it's clearer to say they aren't visible ON those areas. Second, it uses the wrong verb tense (past perfect) in passive voice, which changes the meaning somewhat. This states that sunspots were not visible on the poles and equator in the past, but doesn't say anything about the present!
(E) appear as dark spots on the Sun's surface, which have never been sighted on
This option does use the correct verb tense, but it is still INCORRECT because it uses the term "appear" rather than "visible," which is much clearer.
As you can see, starting your process with #2 on our list is much more complicated and doesn't help you eliminate large chunks of options easily. You can certainly answer a question this way, but it may take you MUCH longer to arrive at the correct answer!
Don't study for the GMAT. Train for it.