The correct answer is (c). Mutation is a change in the base sequence of a gene. This can be caused by errors in DNA replication, exposure to mutagens, or other factors. Mutations can be harmful, beneficial, or neutral. Harmful mutations can cause genetic diseases, while beneficial mutations can lead to evolutionary adaptations. Neutral mutations have no effect on the organism.
Breeding is the process of selecting organisms with desirable traits and mating them to produce offspring with those traits. Cloning is the process of creating an identical copy of an organism. Fusion is the process of combining two cells to create a new cell.
Breeding, cloning, and fusion do not involve changes to the base sequence of a gene. Therefore, they are not mutations.