Given the task definition and input, reply with output. In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Ethologists usually study how animals behave in their natural environment., Fact2: Ethology is the study of behavior., Question: What is the term used for an individual who is learning ethology? (A) Biologist (B) ruler (C) Behaviorist (D) Ethologist (E) humans (F) A Greek letter (G) recovery (H) Mechanic
D