GmatKiss wrote:Presenting a proper question in the first place!!!!

In order to evenly and effectively paint a rough surface, it is necessary to sand it and apply primer before applying the paint.

(A) it and apply primer before applying the paint
(B) it and prime it and paint it - awkward
(C) it, then prime it, then paint it - awkward
(D) the surface and apply primer before you apply paint to the surface - redundant
(E) the surface, apply primer to the surface and then paint it. - redundant

Sometimes we need to move an awkward subject or object to the back of the sentence. In these cases, we put an "it" in the sentence where the subject or object used to be. We call this use of it "Placeholder It". Do not look for a noun antecedent for a "Placeholder It".

Just look an example:

To Resist temptation is futile. (Awkward)
The subject of the sentence is the infinitve phrase to resist temptation. Although this sentence is grammatically correct, the GMAT rejects similar sentences on stylistic grounds.

IT is futile to resist temptation. (Correct)

"It" is now the grammatical subject. As a pronoun, it refers to the infinitive phrase. Under other circumstances, "it" can not normally refer to an infinitive.

Consider one more example:

It would hardly be fair for the meatpacking industry to blame regulators for the harm that it has inflicted upon itself in the sub-prime meat sector.

Above sentence is correct.

Reason: The antecedent of the first "it" (which is a Placeholder It) is the long infinitive phrase "to blame.....mortgage sector". The antecedent of the second "it" and of "itself" is industry.


Now if you apply this rule to the option A, I think it will be clear to you.

Note: All the wording used above is from MGMAT SC guide with all rights reserved