This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Biology, Subject name: Biochemistry
[{'content': "Tell the bond (X, Y, Z) in the structure of DNA: \nSelect and explain. \nA. X-Hydrogen bond, Y-beta N glycosidic bond, Z-3' 5' phosphodiester bond, B. X-Hydrogen bond, Y-beta O glycosidic bond, Z-2' 5' phosphodiester bond, C. X-Hydrogen bond, Y-beta N glycosidic bond, Z-2' 3' phosphodiester bond, D. X-Hydrogen bond, Y-phosphodiester bond, Z-3' 5' beta N glycosidic bond", 'role': 'user'}, {'content': "Answer: A \nExplanation: X is the bond between the two nitrogenous bases. This is hydrogen bond.There is double bond between A and T, triple bond between G and C. Y is the bond between nitrogenous base and sugar. This is beta-N glycosidic bond, which is a covalent bond. This bond is between C1 of sugar and N9 of purines and N1 of pyrimidines. Z is the bond between sugar and phosphate. This is 3' 5' phosphodiester bond.", 'role': 'assistant'}]