I think its A. and C. I'm not 100% sure
We can confirm that a person with very toned muscles likely has tightly packed myofibrils.
<h3>What are myofibrils?</h3>
These fibers are the protein filaments that cause contractions in the structure of the muscle. Weight training tones muscles by increasing the number of myofibrils in a sarcomere, thus increasing its capacity to produce force.
Therefore, we can confirm that a person with very toned muscles likely has tightly packed myofibrils.
To learn more about muscle fibers visit:
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