Sentence Correction

Q 1. Except for one class in history and one in biology, all the student's graduation requirements have been fulfilled.

a. Except for one class in history and one in biology, all the student's graduation requirements have been fulfilled.
b. Except for needing to take one class in history and one in biology, the student has fulfilled all of his requirements for graduation.
c. The student has fulfilled all his graduation requirements except for one class in history and one in biology.
d. Except for one history class and one biology class, the student has fulfilled all of his graduation requirements.
e. Aside from the history class and biology class that he needs to take, the student's graduation requirements have all been fulfilled.

Can some one explain the answer and reasons

Except for one class in history and one in biology, all the student's graduation requirements have been fulfilled.

a. Except for one class in history and one [WHAT?] in biology, all the student's graduation requirements have been fulfilled.
b. Except for needing to take one class in history and one [WHAT?] in biology, the student has fulfilled all of his requirements for graduation.
c. The student has fulfilled all his graduation requirements except for one class in history and one [WHAT] in biology. - PASSIVE and NOT PARALLEL
d. Except for one history class and one biology class, the student has fulfilled all of his graduation requirements.
e. Aside from the history class and biology class that he needs to take, the student's graduation requirements have all been fulfilled. - completely awkward

IMO: D

Hi GmatKiss,

Can you explain a little more about why option is wrong. " one class in history and one in biology" seems parallel as class is implied in the second part.

D is parallel and good to be answer.