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
Commonest cause of secondaryamenorrhea is : 
Select and explain. 
A. TB, B. Pregnancy, C. Post pill amenorrhea, D. Anaemia
B: Pregnancy
Answer: B: Pregnancy 
Explanation: Pregnancy