Which of the following BEST defines muscles?

HURRY PLS

B. tough strong tissues that provide energy to perform physical activities.

Tendons and cartilage are connective tissues.Fibers are fibers not muscles.

Hope you could get an idea from here.

Doubt clarification - use comment section.

Ithink it's d or it can be itger

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)