**Core Concept**
Wilson's disease is a genetic disorder characterized by excessive accumulation of copper in the body, particularly in the liver, brain, and other organs. This accumulation leads to cellular damage and various clinical manifestations, including neurological and hepatic symptoms.

**Why the Correct Answer is Right**
Testicular atrophy is not a characteristic feature of Wilson's disease. The disease primarily affects the liver, brain, and other organs, but it does not typically cause testicular damage or atrophy. The other options are all possible manifestations of Wilson's disease: **haemolytic anaemia** can occur due to copper accumulation in red blood cells, **chorea** is a neurological symptom related to copper toxicity in the brain, and **chronic active hepatitis** is a liver complication resulting from copper accumulation.

**Why Each Wrong Option is Incorrect**
**Option A:** Haemolytic anaemia is a possible complication of Wilson's disease due to copper accumulation in red blood cells, leading to their premature destruction.
**Option C:** Chorea, a neurological symptom, is a well-documented feature of Wilson's disease, resulting from copper toxicity in the brain.
**Option D:** Chronic active hepatitis is a liver complication of Wilson's disease, caused by copper accumulation in liver cells, leading to inflammation and damage.

**Clinical Pearl / High-Yield Fact**
Wilson's disease is an autosomal recessive disorder caused by mutations in the ATP7B gene, which plays a crucial role in copper transport and metabolism. Early diagnosis and treatment can significantly improve outcomes and prevent long-term complications.

**✓ Correct Answer: B. Testicular atrophy**