A biological species A always looks different from other spe

A biological species:

A) always looks different from other species

B) always has a different chromosome number from that of other species

C) is reproductively isolated from other species

D) never occupies the same niche as other species

Solution

Speciation only occurs only when an individual of a particular species becomes reproductively isolated from the rest.

So the answer is: C) is reproductively isolated from other species.