Final answer:
Monkeys have a complex diet, use tools, live in large social groups, and possess prehensile tails.
Step-by-step explanation:
The primate species described as having a complex diet, using tools, living in large social groups, and having prehensile tails are the monkeys. The monkeys belong to the group called ceboids, which consists of the monkeys of South America. They have tails that can hang from branches of trees and are known for their agile movement and intelligence. Some examples of monkeys with these characteristics are marmosets, howler monkeys, and spider monkeys.