Steve Is an Avid Cell Phone User

Steve is an avid cell phone user.He checks it all the time.One day,Steve could not find his cell phone.As a result,Steve became anxious and upset.After looking in the car,he found it and became relaxed.When finding the cell phone causes Steve to become relaxed,this is referred to as ______.

A) primary reinforcement
B) positive reinforcement
C) negative reinforcement
D) conditioning contrast