Answer:
The correct answer will be option-Base analog
Explanation:
5-bromodeoxyuridine is a synthetic nucleoside which is formed by deaminating the 5-Bromodeoxycytidine.
The BrdU once incorporated in the DNA of replicating cell during S phase binds the adenine which shows that it replaces the thymidine which usually binds the adenine.
Since BrdU binds the adenine, therefore, it acts as the analogue of the thymidine and also can cause mutations thus acts as a mutagen.
Therefore, it acts as a base analog and thus is the correct answer.