Which of the Following Correctly Describes the Structure of DNA

Multiple Choice

Which of the following correctly describes the structure of DNA as determined in 1953? 1.A phosphate backbone with sugars linked together by nitrogenous base bonds.
2) A sugar-phosphate backbone with nitrogenous bases linked together by weak bonds
3) A nitrogenous base backbone with sugars linked together by phosphate bonds.

A) 1
B) 2
C) 3
D) 1 and 3
E) None of these