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 case of vasectomy is said to have failed as the vasectomised person's wife gives bih to a child ten months after the operation. Which one of the following is the most probable cause : 
Select and explain. 
A. Failure of the husband to use a condom after vasectomy, B. Surgical failure, C. Recanalisation, D. Wife had extra -- marital contact
A: Failure of the husband to use a condom after vasectomy
Answer: A: Failure of the husband to use a condom after vasectomy 
Explanation: Failure of the husband to use a condom after vasectomy