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
A patient with amenorrhea had bleeding after giving a trial of progesterone. This implies:a) Sufficient estrogenb) Sufficient progesteronec) Normal ovarian functiond) Intact endometriume) Intact pituitary axis 
Select and explain. 
A. ade, B. bde, C. abd, D. ad
A: ade
Answer: A: ade 
Explanation: None