How thoroughly should you review answers and explanations?

How thoroughly should you review answers and explanations when doing Qbank questions (usmlerx, uworld, kaplan, and etc)? Its taking me a long time to review questions because im trying to go over each answer choices, find them on first aid, review related topic on it, and do that for each question. For example, Question: foul smelling diarrhea after campying with motile pear shaped trophozoite? Answer choice: A. Giardia B. E coli C. Histoplasma D. Gi cancer E. Norovirus I... How thoroughly should you review answers and explanations?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums