Answer : 4. "All the above"
Explanation :

Answer: D) All the above Explanation: Nitrogenous base: A molecule that contains nitrogen and has the chemical properties of a base.   DNA and RNA ::   The nitrogenous bases in DNA are Adenine (A), Guanine (G), Thymine (T), and Cytosine (C).   Whereas the nitrogenous bases in RNA are the same, with one exception: Adenine (A), Guanine (G), Uracil (U), and Cytosine (C).