Dora has been admitted to veterinary school and is excited to begin. She has an intense fear of dogs, probably stemming from when she was bitten by a dog many years ago. Dora knows that she must overcome this fear before she begins vet school. She finds a therapist who has her stand in a room with five dogs; the therapist remains in the room with her. After a few minutes of thinking that she would need to run out or start screaming, she realized that the dogs were actually not hurting her. After about an hour and a half, she noticed her anxiety level was substantially lower than it was before she entered the room. The technique seemed to be working. Dora's therapist was using the _____ technique known as _____