According to the biological species concept, individuals belong to the same species if they can interbreed in nature and produce viable, fertile offspring. prezygotic and postzygotic barriers ensure that members of different species do not reproduce with one another. this diagram shows some of these barriers along with examples of the barriers at work.

The correct answer for the question that is being presented above is this one: 

Prezygotic:
behavioral isolation: differences in mating rituals or displays
temporal isolation: differences in the timing of matinghabitat isolation: differences in habitat occupiedmechanical isolation: reproductive structure incapabilitygametic isolation: sperm and egg are incompatible

Postzygotic
reduced hybrid viability: hybrid offspring are produced but are feeble or unable to compete for matesreduced hybrid fertility: hybrid offspring are produced but are sterile