Alexis was diagnosed with obsessive-compulsive disorder because she has to check the locks on her house and car many times before she can leave them. her therapist asks her to lock a door then takes away the keys so alexis cannot lock the door again. taking away the keys is and locking the door is

a. systematic desensitization; exposure
b. exposure; response prevention
c. response prevention; exposure
d. response prevention; systematic desensitization