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: Pathology
All are risk factor for breast ca except - 
Select and explain. 
A. OCP, B. Early mensturation, C. Family history, D. Late menopause
A: OCP
Answer: A: OCP 
Explanation: Ans. is 'a' i.e., OCP