Answer:
D) The mutation must be in a gamete of the individual.
Step-by-step explanation:
Heritability of mutations requires them to occur in germ cells /gametes only. Mutations in somatic cells are not transmitted to the next generations. The male and female gamete fuse together to form the zygote which in turn develop into new individuals. Hence, any mutation in the DNA of these gametes will be carried to the offspring.