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: Medicine
All of the following are present in the acrosomal head of spermatozoa except? 
Select and explain. 
A. alkaline phosphatase, B. acid phosphatase, C. acrosomase, D. hyaluronidase
A: alkaline phosphatase
Answer: A: alkaline phosphatase 
Explanation: None