Final answer:
The student's question pertains to the classification of a prosimian, and among the listed options, the Lemur is the only animal that falls into the prosimian category, known for being nocturnal and having smaller brain sizes compared to anthropoids.
Step-by-step explanation:
The prosimians are a group of primates that include species like the bush babies of Africa, the lemurs of Madagascar, and the lorises of Southeast Asia. According to the information provided, among the options listed — Gibbon (a lesser ape), Chimpanzee (a great ape), Lemur (a prosimian), and Baboon (a monkey of Africa) — the one classified as a prosimian would be the c. Lemur.
Prosimians are generally nocturnal and have smaller brain sizes compared to anthropoids, which include monkeys, lesser apes like gibbons, and great apes such as chimpanzees. Lemurs are specifically mentioned as part of the prosimian group, distinguishing them from the other options provided, which are categorized under anthropoids.