Answer: The following is a postzygotic isolating barrier :
Explanation:
Reproductive isolation occurs when barriers prevent two populations from interbreeding , keeping their gene pools separate.
We can find the Prezygotic isolation that occurs before fertilization can happen.
And the Postzygotic insolation barriers are the reproductive insulation processes that act after the mating. They are all that concern the viability of the individuals produced.
Prezygotic isolation barriers can be temporal, behavioural, geographic , ecological or mechanical; whereas postzygotic isolation barriers include the inviability, infertility or breakdown of hybrid organisms