All of the above would be the best answer because they all involve using your body in a physical way to release the stress you may or have incurred. Stress can be harmful on the body. For example: You may not be sleeping well because you are stressed. Performing cardio such as running or lifting weights could help your body tire and release that stress so you may sleep easier at night. Or perhaps you are stressed because you cannot focus. Performing stretches or yoga could help you relax and relieve stress so that you may be able to focus better.
The breathing process is controlled by the central nervous and respiratory systems. Hope I helped ^-^
