This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
Minimum dose of estrogen in combined OCP's 
Select and explain. 
A. 20mcg, B. 30cg, C. 35mcg, D. 50mcg
A: 20mcg
Answer: A: 20mcg 
Explanation: .