This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetic and genetic disorders, Subject name: Pediatrics
Causes of female pseudohermaphrodism is ____________ 
Select and explain. 
A. 17-alpha hydroxylase deficiency, B. 21-alpha hydroxylase deficiency, C. Mixed gonadal dysgenesis, D. All of the above
B: 21-alpha hydroxylase deficiency
Answer: B: 21-alpha hydroxylase deficiency 
Explanation: 21 alpha hydroxylase dficiecy is characterised by deficiency of glucocoicoids and mineralocoritcoids with elevated androgen level. Excess androgen production during the critical period of fetal development leads to masculinization of female. female pseudohermaphroditism is a condition in which the gonadal sex is female, but the external genitalia are masculinized. Reference: Ghai textbook of pediatrics 8th edition pg 539