**Core Concept**
Rheumatic chorea, also known as Sydenham's chorea, is a neurological disorder that occurs in children as a complication of acute rheumatic fever (ARF). It is characterized by involuntary movements, particularly of the face, arms, and legs, and is often accompanied by emotional changes and behavioral problems.

**Why the Correct Answer is Right**
Rheumatic chorea is associated with autoantibodies against the basal ganglia, particularly against the dopamine D2 receptors. This immune-mediated reaction disrupts normal motor function and leads to the characteristic choreiform movements. The exact mechanism is not fully understood, but it is thought to be related to the body's immune response to group A beta-hemolytic streptococcal (GABHS) infections.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because rheumatic chorea is not directly related to the carditis or arthritis that are also manifestations of ARF. While these conditions share a common underlying cause, they are distinct clinical entities.
**Option B:** Incorrect because the chorea is not a manifestation of a neurodegenerative disease, but rather an acute and reversible condition associated with the immune response to GABHS infections.
**Option C:** Incorrect because the chorea is not a direct result of a genetic predisposition, but rather an acquired condition that occurs in response to an infection.

**Clinical Pearl / High-Yield Fact**
Rheumatic chorea often resolves spontaneously within weeks to months, but can recur with subsequent episodes of ARF. Treatment typically focuses on managing symptoms and preventing further episodes of ARF through antibiotics and anti-inflammatory medications.

**Correct Answer:** D.