This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Which of the following has a direct role in apoptosis? 
Select and explain. 
A. Nitric oxide, B. Adenylcyclase, C. cAMP, D. Cytochrome C
D: Cytochrome C
Answer: D: Cytochrome C 
Explanation: Mitochondria contain a protein called cytochrome c, which is its lifeline in intact mitochondria but releases this protein into the cytoplasm of the cell in apoptosis.Harshmohan textbook of pathology 7th edition.