One who studies insect life:

Geologist
Zoologist
Entomologist
Botanist

The correct answer is C. Entomologist.

An entomologist is a scientist who studies insects. They may study the behavior, anatomy, or ecology of insects. Entomologists may also study the impact of insects on humans and the environment.

A geologist is a scientist who studies the Earth’s physical structure and history. They may study the composition of rocks, the formation of mountains, or the history of climate change.

A zoologist is a scientist who studies animals. They may study the behavior, anatomy, or ecology of animals. Zoologists may also study the impact of animals on humans and the environment.

A botanist is a scientist who studies plants. They may study the structure, function, or growth of plants. Botanists may also study the impact of plants on humans and the environment.