Mercedes just stubbed her toe on the edge of her bedpost. in response, her brain will most likely signal the release of

The correct answer is endorphins.

Explanation:

An array of hormones discharged within the nervous system and the brain and exhibiting various physiological activities known as endorphins, they stimulate the opiate receptors of the body, leading to an analgesic effect. The two most general elements that result in the discharging of endorphins are stress and pain. With high levels of endorphins, one feels lesser negative influences of stress and less pain. Thus, stubbing of the toe on the edge of the bedpost will result in the discharging of hormone endorphin.

the answer is d p: cell, q: organ, r: organ system, s: tissue