727

[vaivish]

727. The demand for airplane mechanics is expected to grow about ten percent a year in the next decade, largely because new federal rules calling for major modifications to older planes and because the airlines are adding hundreds of new jets.
(A) new federal rules calling for major modifications to older planes
(B) new federal rules, which call for major modifications to older planes
(C) new federal rules call for major modifications to older planes
(D) major modifications to older planes called for by new federal rules
(E) major modifications to older planes are called for according to new federal rules

Oa is C although it is not parallel. A seems be more parallel. Pl explain.

[yogesh_kkk]

because the verb is missing in A
parallel construction is
because new federal rules are calling for major modifications to older planes and because the airlines are adding

C is correct as call is verb

[Stockmoose16]

because the verb is missing in A
parallel construction is
because new federal rules are calling for major modifications to older planes and because the airlines are adding

C is correct as call is verb

What do you mean the verb is missing from A? CALLING is the verb.

[reachac]

C is parallel, look at it this way,

The sentence structure is X because Y(reason) and because Z(reason)

both X and Y must have the same form. Now here Z " the airlines are adding hundreds of new jets" has no 'of' after because. So X should alos be similar in construction. A would be correct only if the because were follwed by an 'of'. But it is not there + alos not allowed in this case.
C is perfectly parallel in that X and Y are parallel.