Well here goes my analysis...

1) IMO E

initially i just went for parallelism by...,by.... and by.... so this narrowed down to D and E.

now salmon's numbers "are reducing" talks bout the current situation whereas "have been" talks that the process has started in the past and is still continuing... hence E is better than D

2) IMO D

i don't have a solid explanation...i just went for D because it sounds right..

Correct ans:
[spoiler]1. e
2. d[/spoiler]

PAB2706, u got it correct. My doubts:
1. How can we use "numbers of x" because as per my understanding it should be "number of x" and it takes singular verb.
2. Don't we need a comma to separate adjectives from the noun here which is used in choice b?

hey vaibhav,

1)you are right numbers OF is a wrong usage.. but you are missing the point here.... wild salmon's numbers is right for example...you will understand if i give u a relevant example.. " During the partition, muslims left india in large numbers." similarly "salmon's numbers" is right usage showing large quantity. i dnt know whether you are following what i mean to say..i am sloppy when it comes to explaning grammar

Thanks PAB2706,
Your example is pretty clear. I guess you mean to say here "numbers" is used as noun. Thanks again.

Can u comment on ques. 2?

vaibhav.iit2002 wrote:What are the correct ans. of these SCs? Please help

Please see the answers and my queries in next post that I'll post soon

for the second one check Parallelism
1 -- says both rooted
so has to be in the form both X and Y
where X and Y verbs .. and Y Missing so leave it
2 --- has the same problem
3 --- who produced a body rooted is given as an non essential modifier (since in commas) try droping it and you will find the answer doesn't make sense .
4 ----correct answer perfect uses that, which in turn plays the role of essential modifier
5 --same problem as 1 and 2
hope this helps

kaulnikhil, thanks for the explanation. I got it.