**Core Concept**
Heberden's Arthropathy is a degenerative joint disease characterized by the development of bony enlargements at the distal interphalangeal joints (DIP joints) of the fingers. This condition is a hallmark of osteoarthritis and is often associated with aging and repetitive joint stress.

**Why the Correct Answer is Right**
Heberden's Arthropathy results from the progressive wear and tear of the articular cartilage and underlying bone in the DIP joints. This leads to the formation of bony spurs or osteophytes, which cause the characteristic bony enlargements. The pathophysiology involves the activation of various enzymes, including matrix metalloproteinases (MMPs), which degrade the cartilage matrix, and the release of pro-inflammatory cytokines, which promote joint inflammation.

**Why Each Wrong Option is Incorrect**
**Option A:** Heberden's Arthropathy primarily affects the proximal interphalangeal (PIP) joints, which is incorrect as it specifically affects the DIP joints.
**Option B:** Bouchard's nodes are associated with osteoarthritis, but they occur at the PIP joints, not the DIP joints, making this option incorrect.
**Option C:** Rheumatoid Arthritis (RA) is an autoimmune disease that affects multiple joints, including the hands, but it primarily affects the PIP and metacarpophalangeal (MCP) joints, not the DIP joints.

**Clinical Pearl / High-Yield Fact**
Remember that Heberden's Arthropathy is often associated with a positive "squaring" of the DIP joints, which is a characteristic clinical finding. This can be a useful clue in diagnosing osteoarthritis.

**Correct Answer: D. DIP joints of the fingers.**