I believe the answer is endogenous
I think the correct answer would be that it is a result from conditioning. His fear resulted from a traumatic experience wherein his body reacted in a way that it became his fear. The body was conditioned to feel fear when in those situations. Hope this answers the question.
Answer:
B. the Great Plains
Explanation:
During the Dust Bowl period, severe dust storms, often called “black blizzards” swept the Great Plains.
