<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 17-year-old girl presents to the gynecologists office due to lack of menarche. She has been sexually active with 1 male lifetime partner and always uses a condom. Her mother believes that breast development started at 11 years old. On exam, she is a well-appearing, non-hirsute teenager with Tanner V breast and pubic hair development. Her pelvic exam reveals normal external genitalia, a shortened vagina, and the cervix is unable to be visualized. Initial laboratory testing for hormone levels and karyotype is normal, and imaging confirms what you suspect on exam. What is the most likely cause of her lack of menstruation?? A: 5-alpha reductase deficiency, B: Androgen insensitivity, C: Müllerian agenesis, D: Premature ovarian failure, E: Turner syndrome,  <response>: This is a question about a 17-year-old girl who has not started menstruating yet. She has normal secondary sexual characteristics except for a shortened vagina and inability to visualize the cervix on pelvic exam. Lab testing and imaging are consistent with the pelvic exam findings. This suggests a congenital anomaly of the reproductive tract. The choices given are different causes of lack of menstruation. Based on the information provided, the most likely cause is Müllerian agenesis choice C, which is a congenital anomaly where the vagina and uterus are underdeveloped or absent. Androgen insensitivity choice B can also cause lack of menstruation but would not cause shortened vagina or inability to see cervix. The other choices are less likely based on the details provided.C: Müllerian agenesis 