IMHO it's C, although this is another weirdly worded problem. There is no link between accepted applicants and people who enroll (if you take stmt 1 by itself), nor is there any link between accepted students and those who apply.
However, if you consider that making a deposit = enrolling in classes, then taking both stmts would help solve the thing:
15% of applicants are accepted and 80% of accepted candidates enroll means that 15%*80% of applicants actually enroll.