If organisms are unable to generate enough genetic diversity to survive in a changing environment, they

Sometimes go extinct is the correct answer.

Explanation:

Genetic variation or diversity is very important for a species if it wants to survive. This diversity is basically the very first step of evolution, where adaptation is also involved. So, if a population with low genetic diversity is exposed to a disease, the population might eventually disappear because it cannot adapt to the new context.

b would be the answer