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. tRNA, B. mRNA, C. rRNA, D. 16S RNA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: t RNA has unusual bases such as Dihydrouracil (DHU), pseudouridine, hypoxanthine. Ref: Textbook of Biochemistry By DM Vasudevan, 3rd Edition, Pages 355-6 ; Lippincott Biochemistry, Pages 379, 344', 'role': 'assistant'}]