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: Biochemistry
[{'content': 'Which of the following combinations of biologically active molecules does vitamin A consists of \nSelect and explain. \nA. Retinol, retinal and retinoic acid, B. Retinol, retinal and tetrahydrofolate, C. Retinal, conjugase and retinoic acid, D. PABA, retinal and retinaldehyde', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Retinol, Retinal, and Retinoic acid', 'role': 'assistant'}]