Answer:
b. gametic isolation or temporal isolation
Step-by-step explanation:
Gametic isolation is a type of prezygotic barrier where the gametes (egg and sperm) come into contact, but no fertilization takes place.
Temporal isolation - separation in time such that reproduction occurs at different times of the day, or season or even years. For example, consider the time of day when Evening primrose or Morning glory flowers. The Western spotted skunk mates late summer, whereas the eastern spotted skunk mates in late winter.