The numbers of is always incorrect. Number is singular. This rules out B and D.

A has subject verb agreement error in the recent growth (sing)...are (plu)

E - use of possessive form is incorrect. Possessive form is used to show belonging. We cannot say that numbers belong to vehicles.

C is right.

yes niks i have also choosen C

In this case actually, it's "the number" which is singular and not just "number" . If it would have been "a number" then it would have been plural and would have followed by "are" instead of "is"

navami wrote:In this case actually, it's "the number" which is singular and not just "number" . If it would have been "a number" then it would have been plural and would have followed by "are" instead of "is"

Nope. Article a cannot precede a plural noun. So, 'a number' is singular.
a number...are is incorrect

The original sentence supplies the incorrect plural verb "are" to refer to the singular subject "growth."

(A) This answer choice is incorrect as it repeats the original sentence.

(B) This answer choice uses the unidiomatic construction "numbers of vehicles" rather than the
appropriate idiom "the number of vehicles." Furthermore, the plural verb "are" does not agree with the
singular subject "growth."

(C) CORRECT. This answer choice supplies the correct singular verb "is" to refer to the singular
subject "growth." In addition, this choice uses the appropriate idiomatic construction "the number of
vehicles."

(D) This answer choice uses the unidiomatic construction "numbers of vehicles" rather than the
appropriate idiom "the number of vehicles."

(E) In this answer choice, the plural verb "are" does not agree with the singular subject "growth."
Furthermore, the possessive phrase "vehicles' numbers" is awkward and unidiomatic. The appropriate
idiom is "the number of vehicles."