Which Scenario Describes Extinction

Which scenario describes 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 driveway, 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 first 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 driveway, like her dealer used to do in his car.
D) Alexis uses cocaine. When her dealer pulls into her driveway, her hands shake and her heart pounds, even though she has not yet consumed the drug.