Which change agent requires multiple populations?*1 pointMutationsSexual reproductionGene flowGenetic drift

The change agent that requires multiple populations is Gene flow.

Here's why:

1. Mutations: These are changes in the DNA sequence of a cell's genome and can occur in individuals, not requiring multiple populations.

2. Sexual reproduction: This involves the combination of genetic material from two individuals to create offspring, but it doesn't necessarily require multiple populations. It can occur within the same population.

3. Gene flow: This is the transfer of genetic variation from one population to another. If genes are carried by individuals from one population to another, then they can introduce new genetic material to the receiving population. Therefore, gene flow requires multiple populations.

4. Genetic drift: This is a change in the frequency of an existing gene variant in a population due to random sampling and chance. It can occur in a single population, not requiring multiple populations.