Answer:
The correct answer would be B. post-zygotic barrier.
Reproductive isolation is a type of evolutionary mechanism by which inter-breeding between organisms of two species is prevented.
It includes pre and post zygotic barriers.
Pre-zygotic barriers include methods which prevent mating of two organisms.
In contrast, post-zygotic barriers are those by which mating occurs but the hybrid either is sterile or not viable or both.
Thus, infertile offspring of tiger and lion would be a type of post-zygotic barrier.
