Which theory supports the fact that a person who goes skydiving for the first time is likely to feel fear before the activity followed by relief after completing the activity?

correct answer is a. and d.

energy and particles

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.