How can reducing gene flow between two populations promote speciation?

• A. It guarantees that both populations remain genetically identical because no new alleles can arise without migration.
• B. It immediately creates postzygotic isolation by causing all hybrids to be sterile in the next generation.
• C. It allows populations to diverge genetically through mutation, natural selection, and genetic drift, which can lead to reproductive isolation.
• D. It increases the frequency of interbreeding between populations, preventing genetic differences from accumulating.

Answer: (C)