Which body system is the most important

nervous system

While your heart is a vital organ, the brain (and the nervous system that attaches to the brain) make up the most critical organ system in the human body. The human nervous system is responsible for coordinating every movement and action your body makes.

Nervous System

Explanation: The nervous system that attaches to the brain make up the most critical organ system in the human body. The human nervous system is responsible for coordinating every movement and action your body makes.

answer: my answer would be a) scheduling workouts with your friend for consistent days and time

explanation:

for me personally i would be much more likely to go to the gym with a friend because i wouldn't want to cancel on them or stand them up.