An economy that has the lowest opportunity cost for producing a particular good is said to have a(n):

comparative advantage

An economy that has the lowest opportunity cost for producing a particular good is said to have: a comparative advantage. The concept of comparative advantage is based upon: relative opportunity costs

Explanation:

the answer to the question is punishment. or more specifically, positive punishment.

positive punishment occurs when a behavior is given a negative consequence for the individual doing the behavior.

sara no longer wants to ask questions (the behavior) because she is ridiculed by mr. smith (the punishment).

reinforcement is inaccurate because reinforcement always gives positive consequences for the individual doing the behavior, be it by introducing a pleasant consequence or removing an unpleasant one.