A. avoid long study sessions.
B. designate a quiet, comfortable area.
C. study the most difficult or important first.
D. the longer you study at one time, the better you remember.
Actualy the real answer is D. It is NOT true that the longer you study at one time, the better you remember. It is very the contrary which is the A option: it is better to avoid long study sessions.So your answer is D.
