**Core Concept**
Ewing's sarcoma is a malignant bone tumor characterized by a specific genetic translocation and distinct histopathological features. It primarily affects children and young adults, with a predilection for the diaphysis of long bones.

**Why the Correct Answer is Right**
The correct answer is **D. Flexner-Wintersteiner rosettes**, which are characteristic of retinoblastoma, a different type of tumor. Ewing's sarcoma is actually characterized by small, round, blue cells (SRBCs) with a "zellballen" (cell ball) pattern and the presence of Homer Wright rosettes, not Flexner-Wintersteiner rosettes. The specific genetic translocation t(11;22)(q24;q12) involving the EWS and FLI1 genes is a hallmark of Ewing's sarcoma, as stated in option C.

**Why Each Wrong Option is Incorrect**
**Option A:** The diaphysis of long bones is indeed a common location for Ewing's sarcoma, making this statement true.
**Option B:** Symptoms of Ewing's sarcoma can resemble those of osteomyelitis, such as pain, swelling, and fever, making this statement true.
**Option C:** The t(11;22) translocation is a classical and specific genetic feature of Ewing's sarcoma, making this statement true.

**Clinical Pearl / High-Yield Fact**
Remember that Ewing's sarcoma is one of the few tumors with a specific genetic translocation, and the presence of Homer Wright rosettes and SRBCs with a "zellballen" pattern is diagnostic. This knowledge can help differentiate it from other malignant bone tumors.

**✓ Correct Answer: D. Flexner-Wintersteiner rosettes**