Definition: You are given a question on a random topic. 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: Which of these television programs did not feature characters introduced on 'Happy Days'?
(A)'Mork & Mindy' (B)'Perfect Strangers' (C)'Joanie Loves Chachi' (D)'Laverne & Shirley'

B