Answer:A-rapid speciation occurs as the population adapt to the environment.
Explanation: Speciation can be defined as the phenomena in which new species evolve from the existing parent species. The speciation can occur because of geographical barriers between the members of the same species, behavioral isolation and reproductive isolation.
In the given situation, a recently formed island may separate the population of the same species. The geographical barrier will prevent the members of the species to copulate. Hence, the separated members will adapt the changes in the new habitat and they will evolve to be developed into new species.
Therefore, rapid speciation occurs as the population adapt to the environment is the correct option.