**Core Concept**
Raynaud’s syndrome is a vasospastic disorder characterized by episodic digital ischemia, often triggered by cold temperatures or emotional stress. It is commonly associated with autoimmune disorders and conditions that affect blood vessel integrity.

**Why the Correct Answer is Right**
Raynaud’s syndrome is typically linked to autoimmune diseases such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA), which can cause inflammation and damage to blood vessels. In contrast, Osteoarthritis (OA) is a degenerative joint disease that primarily affects the cartilage and subchondral bone, without significant inflammation or vascular involvement. The pathophysiology of OA does not typically involve the vasospastic episodes characteristic of Raynaud’s syndrome.

**Why Each Wrong Option is Incorrect**
**Option A:** SLE is a systemic autoimmune disease that can cause vasculitis and Raynaud’s phenomenon, making it a correct association.
**Option B:** Rheumatoid arthritis is another autoimmune disease that can lead to vasculitis and Raynaud’s phenomenon, making it a correct association.
**Option D:** Cryoglobulinemia is a condition characterized by the presence of abnormal proteins (cryoglobulins) in the blood, which can cause vasculitis and Raynaud’s phenomenon, making it a correct association.

**Clinical Pearl / High-Yield Fact**
Raynaud’s phenomenon can be a marker of underlying autoimmune disease, and its presence should prompt a thorough investigation for conditions such as SLE and RA.

**✓ Correct Answer: C. Osteoarthritis**