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: Pathology
[{'content': 'In apoptosis, Apaf-1 is activated by release of which of the following substances from the mitochondria ? \nSelect and explain. \nA. Bel - 2, B. Bax, C. Bcl - XL, D. Cytochrome C', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans is 'd' i.e., Cytochrome CApoptosis is induced by a cascade of molecular events all of which culminate in the activation of caspases. 'In the cytosol cytochrome C binds to a protein called Apaf I (Apoptosis activating factor - 1) and the complex activates caspase 9'", 'role': 'assistant'}]