Answer:
Nitrogenous base
Explanation:
Phosphate and deoxyribose create the "backbone" of a DNA molecule.
Think of the molecule as a ladder.
These(deoxyribose and phosphate) are the sides of the latter.
The nitrogenous bases(A,G,C,T) are the rungs of the ladder.
As the arrow points to the "rung" of the ladder, that means it is a nitrogenous base.
