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
Maximum number of unusual base pairs are seen in 
Select and explain. 
A. rRNA, B. tRNA, C. mRNA, D. snRNA
B: tRNA
Answer: B: tRNA 
Explanation: The transfer RNA show extensive internal base pairing and acquire clover leaf like structures. They contain a significant propoion of unusual bases. These include dihydrouracil (DHU) pseudouridine (Ps) and hypoxanthine. Moreover, many bases are methylated. REFERENCE : DM.VASUDEVAN.TEXTBOOK SEVENTH EDITION ; PAGE NO : 596.