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: Physiology
After ejaculation into vagina sperm retains motility for ? 
Select and explain. 
A. 24hrs, B. 36hrs, C. 72 hrs, D. 1 week
A: 24hrs
Answer: A: 24hrs 
Explanation: Ans. is 'a' i.e., 24hrs"In ejaculated semen the maximum life span of sperm is 24-48 hours at body temperature". -- Indu Khurana