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: Pharmacology
[{'content': 'The most serious side-effect of drug chloramphenicol is: \nSelect and explain. \nA. Candidiasis, B. Photosensitivity, C. Bone marrow depression, D. Angioneurotic oedema', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]