This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Apoptosis, Subject name: Pathology
Apoptosis is regulated by which gene? 
Select and explain. 
A. p53, B. BRAC, C. N-myc, D. RB
A: p53
Answer: A: p53 
Explanation: Ans. is 'a' i.e., p53