Choice 4 is correct. "Consider as" is incorrect. Eliminate 2 & 3. It is either "consider", or "consider to be". 4 is shorter than 1. Eliminate 1. Eliminate 5, as there is no need to repeat the subject by using the subject pronoun "they". Note that 4 is parallel. Critics... consider...and question. Note also the presence of "being" in choice 3. It is not necessary. GMAT test makers often include an unnecessary "being" in an incorrect option.

Note: Correct Idiom is "Consider X Y"

We don't need Considered TO BE or Considered AS- these are wrong in GMAT.


Solution: consider corrections facilities(X) an integral part(Y)

This question also highlights another idiomatic issue.

While in common parlance people often say things such as "I wonder if", "they question if" and "I don't know if", those expressions don't really make sense.

Check out this example. I don't know if it is raining.

If we reverse it we get the following. If it is raining, I don't know.

So what I don't know if it is raining seems to convey is that whether the speaker knows depends on whether it is raining.

So even though people often use if in expressing these types of things, that use is not actually correct. The correct word to use is whether.

I don't know whether it is raining.

So choices A and B can be eliminated, because they both use if where whether would make more sense.

Thanks Marty. The following may also help with this issue. Consider the sentence:
I can't decide if I want to start my GMAT studies with Verbal or Quant.
What's wrong with this statement?
When choosing between two alternatives, "whether" is the proper word of choice to connect the two options. Using the word "if" in the above example unintentionally implies the possibility of not starting your GMAT studies at all! And we know that can't be true.
Correct version: I can't decide whether I want to start my GMAT studies with Verbal or Quant.