**Core Concept**
Gaucher's disease is a genetic disorder caused by a deficiency of the enzyme beta-glucocerebrosidase, leading to an accumulation of glucocerebroside in cells and tissues. This results in a range of systemic symptoms, including anemia, thrombocytopenia, and hepatosplenomegaly.

**Why the Correct Answer is Right**
Tarate-resistant acid phosphatase (TRAP) is an enzyme associated with Gaucher cells, which are characteristic of Gaucher's disease. However, in Gaucher's disease, TRAP activity is not typically resistant to tarate, as the correct answer suggests. Instead, the disease is characterized by a deficiency of beta-glucocerebrosidase, which leads to the accumulation of glucocerebroside. The correct association of TRAP activity with Gaucher cells is actually seen in Niemann-Pick disease, not Gaucher's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Beta-glucocerebrosidase is indeed defective in Gaucher's disease, making this statement true, not false.
**Option B:** Cherry red spots on fundoscopy can be seen in Gaucher's disease due to the accumulation of sphingomyelin in the retinal pigmented epithelium, making this statement true.
**Option C:** Erlenmeyer's flask deformity, also known as Erlenmeyer flask deformity of the femur, is a characteristic radiographic feature of Gaucher's disease, making this statement true.

**Clinical Pearl / High-Yield Fact**
Gaucher's disease is a classic example of a lysosomal storage disorder, where the accumulation of a specific substrate (glucocerebroside) leads to cellular dysfunction and systemic symptoms. This understanding is crucial for diagnosing and managing the disease.

**✓ Correct Answer: D. Tarate resistant acid phosphatase -ve**