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 RNA has abnormal purine bases \nSelect and explain. \nA. t-RNA, B. m-RNA, C. r-RNA, D. 16S RNA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Modified bases are present in tRNA.', 'role': 'assistant'}]