a mutagen is\na living thing that has undergone a mutation.\nan agent that causes a mutation in dna.\na…

a mutagen is\na living thing that has undergone a mutation.\nan agent that causes a mutation in dna.\na mutation that has affected one gene.\nany chemical that can poison living cells.
Answer
Answer:
B. an agent that causes a mutation in DNA.
Brief Explanations:
A mutagen is defined as an agent (physical, chemical, or biological) that can induce changes in DNA sequence, leading to mutations.