Answer:d. need to associate flying with something pleasurable to reduce this fear
Explanation:
Classical conditioning is also known as Pavlovian one(discovered by Russian physiologist Pavlov) and this is a study that is considering learning with the association. In this case, new pleasurable flying will reduce fear because with it's pleasure, the bad memories will be reduced and that will cause a new response in that person, and that would be flying with no fear. It can be also repeated learning until the person gets a new, appropriate response.