Definition: You are given a question on virology. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: PreP is most effective for which group:
(A)Men with frequent unprotected sex (B)Men with infrequent unprotected sex (C)Women with frequent unprotected sex (D)Women with infrequent unprotected sex

A