Specialists are adapted to fill a very narrow niche in a habitat, and when humans or other wildlife cause their one food to change, then the specialist becomes threatened.
Answer:
D. they are unicellular
Explanation:
unicellular organisms are not part of the kingdom animalia .Animalia consists of aves(birds),amphibians,reptiles,mammals and so on and all these organisms are multicellular that is having more than one cell.
