This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sexuality and intersexuality, Subject name: Gynaecology & Obstetrics
Young male presents with delayed pubey with decreased FSH, LH and testosterone. Which of the following is not the possible diagnosis : 
Select and explain. 
A. Kallmann syndrome, B. Klinefelter syndrome, C. Consitiutional delay, D. Dax-1 gene mutation
B: Klinefelter syndrome
Answer: B: Klinefelter syndrome 
Explanation: Klinefelter's syndrome Eunochoid in built Infeile with small penis,testis,varying degree of gynaecomastia Sex chromatin is positive Karyotype is XXY/XXXY Genitalia are small and infantile, genital ducts are wolfian Serum gonadotropins are elevated D.C.DUTTA'S TEXTBOOK OF GYNAECOLOGY,Pg no:444,6th edition