This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Biochemistry
The bases which are present in human DNA? 
Select and explain. 
A. Adenine-guanine-thiamine- uracil, B. Adenine-guanine- cytosine-uracil, C. Adenine- guanine-cytosine-thymine, D. None of the above
C: Adenine- guanine-cytosine-thymine
Answer: C: Adenine- guanine-cytosine-thymine 
Explanation: Double-stranded (ds) Has adenine- guanine-cytosine-thymine Has Deoxyribose DNA does not contain Uracil 2 strands are held together by hydrogen bonds. There are covalent bonds (3' 5' phosphodiester bonds) in sugar-phosphate backbone.