Question

this muscular injury may vary in severity from localized cellular injury to complete rupture of the muscle belly/tendon.
strain
sprain
tendinitis
myasthenia gravis

Explanation:

A strain is a muscular - tendon injury that can range from mild cellular damage to a complete rupture. A sprain involves ligaments, tendinitis is inflammation of a tendon, and myasthenia gravis is an autoimmune neuromuscular disease.

Answer:

Strain