This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': '"Transition mutation" occurs in \nSelect and explain. \nA. A - G, B. A - C, C. A - T, D. D - G', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Replacement of purine by another purine (A to G or G to A ) or pyrimidine by pyrimidine (T to C or C to T ) is called transition mutationRef: DM Vasudevan, 7th edition, page no: 612', 'role': 'assistant'}]