Which one of the following conditions is an example of resource partitioning?

a. two species of squirrels—one that eats acorns from the branches and one that eats acorns that have fallen to the ground
b. two species of mice—one that eats seeds and the other that eats insects
c. two species of birds that eat fruit from the same tree
d. a species of butterfly and a species of bee that pollinate the same flower

The correct option is A. Resource partitioning refers to a situation in which living organisms live together in the same environment in such a way that it is easy for them to co-exist because they are not using the same resources. In the question given above, it will be easy for the two species of squirrels to co-exist because although both are feeding on acorns, they are not feeding on acorns from the same location; one feed on the ground, the other feed on the trees.