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
In - vitro feilisation is indicated in : 
Select and explain. 
A. Anovulatory cycles, B. Tubal block, C. Azoospermia, D. Uterine anomalies
B: Tubal block
Answer: B: Tubal block 
Explanation: Tubal block