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
Which of the following is not helpful in diagnosis of tubal mass in ectopic pregnancy 
Select and explain. 
A. Beta-HCG estimation, B. Hysterosalpingography, C. Transvaginal ultrasound, D. Pelvic examination
B: Hysterosalpingography
Answer: B: Hysterosalpingography 
Explanation: Ans. b. Hysterosalpingography