Answer:The technique described in the scenario is known as "D. flooding or exposure therapy."
Explanation: Exposure therapy involves gradually and systematically exposing the individual to the feared stimulus (in this case, flying) in a controlled and safe environment. The goal is to reduce the fear response by allowing the person to experience the situation they fear without any harmful consequences. In this case, Penelope and the therapist go to the airport, get on a plane, and take a short flight together, which is a form of exposure therapy to help Penelope overcome her fear of flying.