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: Gynaecology & Obstetrics
Ovulation coincides with: 
Select and explain. 
A. High estrogen & high progesterone, B. LH surge, C. Low estrogen & high progesterone, D. Progesterone peak
B: LH surge
Answer: B: LH surge 
Explanation: LH surge