Final answer:
The lemurs are not anthropoids; they are prosimians, which are more primitive primates. Gibbon, orangutan, and gorilla are all anthropoids, more specifically, hominoids.
Step-by-step explanation:
The lemurs are not anthropoids; they are prosimians, which are more primitive primates. Gibbon, orangutan, and gorilla are all anthropoids, more specifically, hominoids. Out of the options provided, the one that is not an anthropoid is the lemur. Anthropoids are a group of primates that include monkeys, lesser apes like the gibbon, and great apes such as the orangutan, gorilla, and chimpanzee.
Lemurs, on the other hand, belong to the group of primates known as prosimians, which are considered to be more primitive and are not categorized as anthropoids. The other three options, gibbon, orangutan, and gorilla, are all part of the group known as hominoids, which includes both the lesser apes (like the gibbon) and the great apes (like the orangutan and gorilla).