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
True about DNA structure: 
Select and explain. 
A. Purines are adenne and guanine & pyrimidines are uracil and cytosine, B. Watson and Crick discovered structure in 1973, C. Deoxyribose-phosphate backbone with bases stacked inside, D. Mainly consists of left handed helix
C: Deoxyribose-phosphate backbone with bases stacked inside
Answer: C: Deoxyribose-phosphate backbone with bases stacked inside 
Explanation: C i.e. Deoxyribose-phosphate backbone with bases stacked inside