Explanation:

Ethology is the scientific study of the typical behavior of organisms in their natural habitat. Ethologists observe and analyze how animals behave in their natural environments, focusing on aspects such as communication, social interactions, mating behavior, and survival strategies.

Here’s a breakdown of the other options:

• (A) Euthenics: This refers to the study of improving human well-being by improving environmental factors like nutrition and living conditions, rather than the behavior of organisms.
• (B) Eugenics: This is the study of improving the genetic quality of the human population, often associated with controversial and unethical practices.
• (D) Ethnology: This is the study of cultures and societies of humans, focusing on their customs, traditions, and social behaviors, not animal behavior.

Therefore, Ethology is the correct term for the study of behavior in natural settings.