Answer: B. Progressive Relaxation
"All you need is focus, attention, and a quiet spot where you won't be distracted. The key with this technique is to tense each muscle group and hold for 5 seconds. Then, you exhale as you let your muscles fully relax for 10 to 20 seconds before you move on to the next muscle group."
I found this info from Healthline.com about progressive relaxation
Hope this helps :)