The increasing of frustrations....
Why is B incorrect?

The subject is frustration -- this is what's causing the need in the sentence.
In A, we have subject of "increasing" which is NOT what's causing the need.
In B, we have a plural subject -- "frustrations" -- that must go with "has
created" later in the sentence. This verb requires a singular subject rather than a plural one.


That leaves C as the correct answer. (D and E start with "Because" which causes the sentence to lose its subject altogether)


-- Veritas Hellp