Regarding the Development of internal genital organs A. The uterus, fallopian tubes, cervix & upper vagina develop from the mesophrenic duct B. The testes secretes testosterone which cause regression of the müllerian ducts in the male fetus C. The vagina is formed by the Urogenital sinus. D. Müllerian agenesis (Mayer- Rokittanky - Kuster - Huser syndromes) is characterized by the absence of the uterus & upper vagina with normal female external genetailia & 46 XX.