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
A 16-year-old female presents with Primary Amenorrhea. Examination shows a Short Blind Vagina, with absent Uterus. The Next Investiga- tion of choice is: 
Select and explain. 
A. Karyotyping, B. IVP, C. Gonadotrophin levels, D. Serum Prolactin
A: Karyotyping
Answer: A: Karyotyping 
Explanation: None