Identify the name of above nitrogen base.

Step-by-step solution

Based on the provided chemical structure: 1. The molecule is a single six-membered heterocyclic ring containing two nitrogen atoms, which identifies it as a pyrimidine base. 2. It has two carbonyl ( -C=O ) groups at positions 2 and 4, making it a 2,4-dioxopyrimidine. 3. There is no methyl group at the 5th position, which distinguishes it from thymine (5-methyluracil). 4. There is no amino group, which distinguishes it from cytosine (4-amino-2-hydroxypyrimidine). 5. Guanine is a purine base (consisting of two fused