The following is an example of mechanical energy a. Riding a bike
b. Eating food
c. The sun
d. A fire giving off heat

The answer is A.

Explanation:

Because it involves motion and kinetic energy.

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.