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
Withdraw! bleeding occurs when progestins administered continuously : 
Select and explain. 
A. Estrogen concentration is sufficient, B. Structural abnormality in the pelvis, C. Associated with endocrine disorder, D. Atrophic endometrium
A: Estrogen concentration is sufficient
Answer: A: Estrogen concentration is sufficient 
Explanation: Estrogen concentration is sufficient