Commonest cause of female pseudohermaphrodism -

Ans. is 'a' i.e., CAH o Female pseudohermaphroditism.Gentotype is XXGonads are ovariesExternal genitalia are virilized (male differentiation).As there is no mullarian inhibiting factor, mullarian duct develops into uterus tubes and ovary. But due to presence of androgen external genitalia are virilized.Causes are;Congenital adrenal hyperplasiafmost common)# 21 hydroxylase deficiency# 11 beta hydroxylase deficiencyMaternal virilizing tumor ArrhenoblastomaMaternal medications with androgen.