Whose-clause: must nouns before and after agree in number?

A question arose here about language in our faculty handbook: should the following be A or B? One group said B, because one contract per instructor (sense). Another group said A, because plural before "whose" needs to be matched by plural after it (grammar). Still another group said it could be either, but that A is likely the "correct" option.

A. All instructors whose initial contracts

B. All instructors whose initial contract

Thank you.

Mark Scott