This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Faster sperm is with which sex chromosome? 
Select and explain. 
A. X chromosome, B. Y chromosome, C. Both same, D. None
C: Both same
Answer: C: Both same 
Explanation: Recent data confirms that Y-sperm does not swim faster than X sperm. Ref: Gray's 39e/p-1289