Answer
a. rarely occurs in highly connected metapopulations.
Work Step by Step
Metapopulations are typically spread out, forming small communities in each of them, so if a disastrous event were to occur and try to wipe out a population, it would not work because it would only affect an isolated population while leaving the whole population unaffected. This relates to inbreeding depression because if something such as a disease were to wipe out a population, it would only affect a small portion of the population rather than the whole, therefore not allowing for inbreeding depression.
