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
Two strands of DNA is/are held by: 
Select and explain. 
A. Glycosidic bond, B. Hydrogen bond, C. Covalent bond, D. Ionic bond
B: Hydrogen bond
Answer: B: Hydrogen bond 
Explanation: Answer( b) hydrogen bond The two strands are held together by hydrogen bond formed by complementary base pairs" (Satyanarayan 4th/75)"The base pairs are held together by hydrogen bonds: two between A and T and three between G and C. These hydrogen bonds, plus the hydrophobic interactions between the stacked bases, stabilize the structure of the double helix.