Which group of animals includes lemurs, monkeys, apes, and humans?

The correct response is the group known as primates. This classification encompasses a diverse array of species, including lemurs, monkeys, apes, and humans. Primates are characterized by specific anatomical and behavioral traits such as flexible limbs, forward-facing eyes, and a high degree of social complexity. These adaptations have allowed them to thrive in various environments, but they share a common evolutionary lineage that distinguishes them from other animal groups.

In contrast, the other classifications—carnivores, herbivores, and insectivores—refer to dietary preferences and particular ecological niches rather than a shared evolutionary ancestry. Carnivores primarily consume meat, herbivores focus on plant materials, and insectivores specialize in eating insects. None of these groups include all the species listed in the question, as they do not share the common characteristics and evolutionary background that define primates. Thus, primates is the only term that accurately encompasses the listed animals.