This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Menstruation, Abnormal Menstruation, Menopausal Physiology and forsight of conception, Subject name: Gynaecology & Obstetrics
Onset of LH surge precedes ovulation by: 
Select and explain. 
A. 12 hours, B. 24 hours, C. 36 hours, D. 48 hours
C: 36 hours
Answer: C: 36 hours 
Explanation: LH surge 36 hrs (24- 36 hrs) before ovulation. LH peak 12 hrs before ovulation.