There are what who study how animals behave in their natural environment.\nOptions:\n- (A) infants\n- (B) heat or cold\n- (C) insects\n- (D) sensory neurons\n- (E) scientists\n- (F) people\n- (G) humans\n- (H) reptiles
Step-by-step reasoning:
(E)
Ethologists usually study how animals behave in their natural environment.

Ethologists are scientists who study animals in their natural habitats.

There are scientists who study how animals behave in their natural environment.

.

The final answer: (E)