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: Pharmacology
Which of the following is given at intervals as a pulsatile therapy ? 
Select and explain. 
A. GnRH, B. GH, C. FSH, D. Estrogen
A: GnRH
Answer: A: GnRH 
Explanation: None