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
Commonest cause of female pseudo hermaphroditism is: 
Select and explain. 
A. Virlizing ovarian tumor, B. Ovarian dysgenesis, C. Exogenous androgen, D. Congenital adrenal hyperplasia
D: Congenital adrenal hyperplasia
Answer: D: Congenital adrenal hyperplasia 
Explanation: The most common cause of female pseudohermaphroditism is congenital (virilizing) adrenal hyperplasia (CVAH or CAH). Ref: Harrison's Principles of Internal Medicine, 14th Edition, Page 2124 and 15th Edition, Page 2178 ; Textbook of Gynecology By D C Dutta, 4th Edition, Page 42 ; Transgenderism and Intersexuality in Childhood and Adolescence: Making Choices By Peggy Tine Cohen-Kettenis, Friedemann Pfafflin, 2003, Page 40