The correct answer is D) trained Gary in a technique called progressive relaxation.
When Gary found out that his new job required some air travel, he sought the help of a clinical psychologist to deal with his intense fear of flying. The clinical psychologist suggested using a procedure called systematic desensitization. As the first step in the process of systematic desensitization, the clinical psychologist trained Gary in a technique called progressive relaxation.
That technique is a relaxation therapy focused on tightening and relaxing muscle groups in a sequence. In 1920, Dr. Edmund Jacobson developed this technique also known as a progressive relaxation therapy. Doing this tightening and relaxing of muscles, the patient is aware of its body sensations. This therapy also helps to relax the mind.