Final answer:
A tendon injury that leads to immediate severe pain, inflammation, and immobility is a severed tendon. Tendinitis, while also painful, is usually caused by repetitive strain and involves inflammation rather than injury.
Step-by-step explanation:
The tendon injury that produces immediate, severe pain, inflammation, and immobility of the affected part is c. Severed Tendon. Tendinitis is the inflammation of a tendon, which typically results from repetitive motions over time that strain the tendons needed to perform tasks. It presents as pain and tenderness around a joint. However, severe cases of tendinitis can lead to a tendon tear, which may necessitate surgical repair due to the connective tissue's slow healing, given its poor blood supply. A fracture refers to a break in the bone and also causes severe pain and immobility but is not a tendon injury.