Mutation, genetic recombination, and gene flow all add what to a population

The answer is; genetic diversity

Genetic diversity is the number of genetic characteristics in a population. Genetic diversity is important in a population especially in its adaptability to a changing environment.   The diversity is acted upon by natural selection and enables the population to evolve with the changing environment.

it's     c       this is a cell (b) with a nucleus (c) containing dna (a). the dna is organized into chromosomes (d). a section of the chromosome that codes for a trait is called a gene (e).

that is wrong, its not thymus.