What is the main cause of competition between two species? a. an overlap in the species’ niches b. the extinction of one species c. genetic drift in both species d. an increase in biodiversity in one species

The answer is A: An overlap in the species’ niches.

Explanation

An overlap in the species’ niches is the main cause of competition between two species.

Species are group of animals or plants that have similar characteristics and are capable of interbreeding.

An overlap in the species’ niches means that  two species whose niches overlap  evolve by natural selection  have more distinct niches thereby resulting in resource partitioning.