Answer:
b) temporal isolation
Step-by-step explanation:
Temporal isolation occurs when two species of similar population dwelling in the same habitat or environment reproduce at different times of the day or at different seasons. They reproduce in the same habitat, but at different seasons, making it difficult for both species of a similar population to interbreed.
Temporal isolation occurs due to the difference in the breeding seasons of the two species of clams living in the same habitat, as one releases gametes into the water in early spring, while the other releases gametes into the water in late summer.