increase in state education spending

[amnesty17]

Part of the proposed increase in state education spending is due to higher enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at a record high.

(A) enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at
(B) enrollment, with a number of students in public schools growing steadily since the mid-1980's and, at nearly 47 million, reaching
(C) enrollment: since students in public schools have grown steadily in number since the mid-1980's and, at nearly 47 million, have reached
(D) enrollment: the number of students in public schools has grown steadily since the mid-1980's and, at nearly 47 million, has reached
(E) enrollment: students in public schools have grown steadily in number since the mid-1980's and, at nearly 47 million, are at

A- wrong because 'the number of students- singular has plural verb- have
C- wrong because students have reached record high , we need number of students
E- wrong because- students are at a record high

B, D
B- is it wrong because since the mid 1980's is a time frame and we need 'has + verb' but we have 'growing', which is a present progressive tense not
present perfect (has/have)

[melguy]

Part of the proposed increase in state education spending is due to higher enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at a record high.

(A) enrollment, since the number of students in public schools have grown steadily since the mid-1980's and, at nearly 47 million, are at
(B) enrollment, with a number of students in public schools growing steadily since the mid-1980's and, at nearly 47 million, reaching
(C) enrollment: since students in public schools have grown steadily in number since the mid-1980's and, at nearly 47 million, have reached
(D) enrollment: the number of students in public schools has grown steadily since the mid-1980's and, at nearly 47 million, has reached
(E) enrollment: students in public schools have grown steadily in number since the mid-1980's and, at nearly 47 million, are at

A- wrong because 'the number of students- singular has plural verb- have
C- wrong because students have reached record high , we need number of students
E- wrong because- students are at a record high

B, D
B- is it wrong because since the mid 1980's is a time frame and we need 'has + verb' but we have 'growing', which is a present progressive tense not
present perfect (has/have)

Please clarify what is your question here?

[vivekchandrams]

'A' number of students. 'The' number is preferable.
And, ya. It needs a present progressive tense. 'Since' makes that mandatory

[amnesty17]

I want to know why B is wrong?