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
In Klinefelter syndrome, all are true except 
Select and explain. 
A. Negative feedback on FSH and LH are lost, B. Decreased Androstenedione levels, C. Hypoplastic male external genitalia, D. Most common cause of primary testicular failure
B: Decreased Androstenedione levels
Answer: B: Decreased Androstenedione levels 
Explanation: In Klinefelter syndrome, since testosterone levels are decreased, negative feedback on FSH and LH is lost.
Increased FSH stimulates Leydig cells, thereby causing elevated levels of Androstenedione.