Word for 'that which requires something'?

If A requires B, then B is the requirement. In this relationship what is A? In this context, I'm describing academic courses where B is a course that fulfills the requirements for course A.

At my university (in the United States Midwest), one would say "ECE 700 (A) is a follow-on course to ECE 600 (B)" and while this implies that B is a prerequisite, it doesn't necessarily require it.

(In my department at least, prerequisites were pretty flexible: transfer students, grad students, and students from other departments---as well as those just plain motivated---could very easily get them waived, so avoiding the suggestion of strict requirements was usually intended.)