During resistance exercise, muscles are

a.
working against a force
b.
repeatedly contracted
c.
concerted in movement
d.
all of the above

answer is a.

most answers will say d but the real one is a.

because C and B are both untrue, A would be correct

A, working against a force

Explanation:

Lots of other answers say D, but they are incorrect. During resistance exercise, muscles work against a force.

answer; (d) braking faster then cars;