Answer:
The correct answer will be- prezygotic and postzygotic
Step-by-step explanation:
Reproductive isolation is the mechanism of speciation which suggests that species gets isolated and do not mate due to reproductive barriers.
These barriers could be the pre-zygotic barriers which represent the barrier before the formation of the zygote that is fertilization of the egg and sperm.
The post-zygotic barrier represents the condition in which the species are isolated due to barriers arisen due to formation of the sterile offsprings.
Thus, pre-zygotic and post-zygotic is the correct answer.