Which is not a feature of mammals as a whole?

A. new world monkeys

B. prosimians

C. hominoids

D. old world monkeys

The correct answer is - C. hominoids.

The hominoids are a group of mammals that do not share the same basic features as the other mammals, speaking in the manner of physical appearance only of course.

The hominoids have started to develop in a much different manner than the rest of the mammals, becoming exclusively bipedal, losing their hair for protection, losing their strength even, becoming species without any particular natural defense mechanisms. This type of mammals became the only one that is reliant on its brain power for its survival, and that makes them unique and not like the other mammals.