Asexual/sexual plant biology please help!

Organisms within a population must compete for resources to survive

What is genetic variation? -(a) each individual in a population has slightly different genes. -(b) some individuals in a population have more genes than others. -(c) each population of a species has slightly different genes. -(d)some populations of a species have more genes than others.

Explain the difference between mutations in sex cell and those in somatic cells