Which condition is a population that descended from a small number of common ancestors more likely to have?

a.) increased frequency of mutation in their genes
b.) decreased ability to survive changing conditions
c.) increased frequency of genes that support survival

B.) decreased ability to survive changing conditions

Evolution is a phenomena in which the heritable characteristics in a population changes over subsequent or successive generations. These characteristics develop due to  expression of genes, the genes are transferred from parents to offsprings during reproduction. Evolution is regulated by two mechanisms natural selection and descends with modifications. Natural selection suggests that only those organisms which have favorable traits which allows them to survive in the changing environment, will reproduce and grow in number. Descent with modification suggests that descent population which are capable for surviving in the changing environment due to natural selection can transmit their traits in future generations, hence will promote evolution.

The population that originates from the small number of common ancestors will be more likely to have decreased ability to survive in a changing conditions because the population will exhibit less genetic variations. The population will acquire least amount of adaptations, and lower the rate of evolution, which cannot support it's survival in the changing environment.