This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infeility (Eggs'plantation!), Subject name: Gynaecology & Obstetrics
Which of the following is the drug of choice for follicle induction for infeility in PCOS: 
Select and explain. 
A. Clomiphene citrate, B. GnRH agonist, C. Combined oral Pills, D. Letrozole
D: Letrozole
Answer: D: Letrozole 
Explanation: Letrozole is the Drug of choice for Induction of ovulation in a case of PCOS; Mode of action- Aromatase Inhibitor Decrease Estrogen production Inhibit Negative feedback on FSH Letrozole preferred over Clomiphene Citrate because less chances of multifetal pregnancy high live bih rate OHSS : Rare with it Given for 5 days (D5-D9) Sta with 2.5mg Max dose 7.5mg