Answer: A population has only one species, while a community has many species.
A community in terms of ecology, is a group or association of the members of two or more types of species living together in a geographical area in a particular time. The members of species interact with each other and plays different roles in a ecosystem. The species defines a population of similar type of organisms which can interbreed and able to produce viable fertile offsprings.
Therefore, A population has only one species, while a community has many species is the correct option.