IMO B

What is the OA?

That pollution harms the environment is self-evident; that immediate government action to combat it is merited by the situation is a matter of debate.

It needs a conditional statement

So options with that are OUT

left with B, C and E

C. Whether to combat the situation is merited by immediate government action

merited by situation and not govt action!!
changes the meaning

E. Whether the government should immediately combat it is merited by the situation

It?
Unclear pronoun reference

Answer is B

Hope it helps

Karan

"if" can not be a subject, B is wrong

C and E is not a sentence

A do not create a structure paralel with first clause; "is merited" is wrong

D is correct

OA is D. BTW, why "If" cannot be the subject? Why things are not parallel in A. Can you pls explain?

I picked D for this question. for the reasons below...

1. The sentence is separated by a ";", so both the sentences should stand by themselves. They cannot be incomplete or dependent on other.

Choice A is passive.. "combat it is merited by the situation "

B. If the situation merits immediate action by the government --- If is used for conditional statements.. If X, then Y or If X, Y.. the sentence is not in this form.

I was got down to C, D, and E.

C, and E are passive.
and Choice D is concise and active.
moreover,

If you see the non-underlined part. the first sentence starts with "That" and it is used to state a clause, I think the same should be for the second sentence. I think I read that the sentences separated by ';' should have have the similar structure.. I am not sure of this rule though..

Can someone explain this in more detail, also clarify my point whether sentences separated by ';' should have similar structure