The right answer is C. be more susceptible to disease and famine.
A population bottleneck (also known as a genetic bottleneck) is, in the study of biological evolution, an event corresponding to the fact that a substantial proportion of the population of a species disappears or is prevented from to reproduce. There is a significantly different type of demographic bottleneck called the founder effect, which occurs when a subset of a population is, at least as far as reproduction is concerned, isolated from the main group.
Population bottlenecks (or bottlenecks) thus reduce genetic diversity, and hence the ability of people to adapt to new environmental constraints such as climate change, or a decline in available resources. This genetic drift can eliminate certain alleles that could, by natural selection, allow the species to adapt.
