5. motor units respond to a stimulus with
a. an all-or-none response
b. a graded response
c, either an all-or-none response or a graded response, depending on the stimulus.

a. life is life.

because life is not always nice.

and life is not always fun and cute.

because health skills are tools and strategies and also practical skills are also something you need to learn (like tools and strategies) and put it in reality.

answer; (d) braking faster then cars;