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
True about congenital adrenal hyperplasia is all except 
Select and explain. 
A. Autosomal recessive disorder., B. 11 - β Hydroxylase deficiency is most common., C. Commonest cause of genital ambiguity at birth., D. Hypoglycemia is seen.
B: 11 - β Hydroxylase deficiency is most common.
Answer: B: 11 - β Hydroxylase deficiency is most common. 
Explanation: 21 - Hydroxylase deficiency is most common.