This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
LH peak occurs how many hours before ovulation ? 
Select and explain. 
A. 36-48 hrs., B. 12-24 hrs., C. 48-72 hrs., D. 72-96 hrs.
A: 36-48 hrs.
Answer: A: 36-48 hrs. 
Explanation: Ans.B.)12-24 hours Ovulation occurs 34 to 36 hours after the onset of the LH surge and about 10 to 12 hours after the LH peak.