Question

dr. liza conducted a sleep study in which half of the volunteers were randomly assigned to scroll through their friends photos on social media right before bedtime. the other half of the volunteers were told to avoid screens at bedtime. dr. liza measured the length of time it took for the volunteers to fall asleep once they got into their beds. which body chemical is most implicated in dr. lizas research? melatonin epinephrine dopamine norepinephrine

Explanation:

Melatonin is a hormone that regulates the sleep - wake cycle. Exposure to screens at bedtime can suppress its production, affecting sleep. The study is about sleep and the impact of screen exposure at bedtime on falling asleep, so melatonin is most relevant.

Answer:

Melatonin