**Core Concept**
The gradual painful limitation of shoulder movements in an elderly individual is suggestive of a condition affecting the rotator cuff or the glenohumeral joint, likely due to degenerative changes, osteoarthritis, or rotator cuff tendinopathy.

**Why the Correct Answer is Right**
The most probable diagnosis is adhesive capsulitis, also known as frozen shoulder. This condition is characterized by a progressive reduction in the range of motion of the shoulder joint due to inflammation and fibrosis of the joint capsule. The pathophysiology involves the formation of adhesions and scar tissue within the joint capsule, leading to pain and stiffness. The condition often affects middle-aged and elderly individuals, with a female preponderance.

**Why Each Wrong Option is Incorrect**
* **Option A:** Osteoarthritis (OA) of the glenohumeral joint can cause pain and stiffness, but it typically presents with a more gradual onset and is often associated with joint space narrowing on radiographs. OA of the glenohumeral joint is less likely to cause a significant reduction in the range of motion.
* **Option B:** Rotator cuff tendinopathy can cause pain and stiffness, but it typically presents with a more acute onset and is often associated with a specific traumatic event. Rotator cuff tendinopathy is less likely to cause a gradual, painless limitation of shoulder movements.
* **Option C:** Glenohumeral dislocation can cause pain and stiffness, but it typically presents with a more acute onset and is often associated with a specific traumatic event. Glenohumeral dislocation is less likely to cause a gradual, painless limitation of shoulder movements.

**Clinical Pearl / High-Yield Fact**
Adhesive capsulitis is often referred to as "frozen shoulder" due to the significant reduction in the range of motion of the shoulder joint. It is essential to diagnose and treat this condition early to prevent long-term disability and improve patient outcomes.

**Correct Answer:** C.