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 yr old female presents with Primary Amenorhea. Examination shows a Sho Blind Vagina, with absent Uterus. The Next Investigation of choice is : 
Select and explain. 
A. Karyotyping, B. IVP, C. Gonadotrophin levies, D. Serum Prolactin
A: Karyotyping
Answer: A: Karyotyping 
Explanation: Answer is A (Karyotyping) : A ,female phenotype along with amenorrhea, absent uterus and sho blind vagina may result from either : - Female (XX) with mullerian agenesis or - Male pseudo-hermophrodite (XY) - Karyotyping is the investigation of choice, to make such a distinction