Which of the Following Scenarios Exemplifies Extinction

Multiple Choice

Which of the following scenarios exemplifies extinction?

A) Alexis is a former cocaine user. Now that she no longer uses, her hands no longer shake and her heart no longer pounds when she hears a car pull into her drive, like her dealer used to do in his car.
B) Alexis uses cocaine. She no longer feels quite the same rush as she did when she fist started using.
C) Alexis is a former cocaine user in recovery. After a relapse, though, her hands shake and her heart pounds when she hears a car pull into her drive, like her dealer used to do in his car.
D) Alexis has relapsed on cocaine. She finds that she doesn't need quite as much of the drug to feel its effects as she did immediately before she stopped using the last time.