Answer:
The only example of temporal isolation is:
a. One species is nocturnal, and the other species is not.
Explanation:
Temporal isolation is a prezygotic barrier, or in other words, a biological barrier that prevents two different species could mate to breed. In our case, the fact that one species mates at the day when the other does it at night is our prezygotic barrier. This type of barriers is based on time, because the involved species can mate in a specific season, an hour or even in different periods like years.
