This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic histology, Subject name: Anatomy
which pa of sperm helps in penetration of zona pellucida ? 
Select and explain. 
A. head, B. middle piece, C. neck, D. acrosome
D: acrosome
Answer: D: acrosome 
Explanation: Acrosome have acrosin enzyme which helps in penetration. Mitochondria is present in middle pa.