**Core Concept**
Ewing's sarcoma is a type of malignant bone tumor that belongs to the family of cancers known as the Ewing's Sarcoma Family of Tumors (ESFT). It is characterized by a specific genetic translocation that involves the **EWSR1** gene. This cancer typically affects the bones or the soft tissue around them.

**Why the Correct Answer is Right**
The correct answer is related to the cell of origin of Ewing's sarcoma, which is believed to be a **neuroectodermal** or **mesenchymal** precursor cell. The exact cell type is still a subject of research, but it is known that Ewing's sarcoma shares some characteristics with **neural crest** cells. The genetic hallmark of Ewing's sarcoma is the **t(11;22) translocation**, which fuses the **EWSR1** gene with the **FLI1** gene, leading to the formation of an oncogenic fusion protein.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while Ewing's sarcoma does involve genetic alterations, the specific origin from this cell type is not accurately described.
**Option B:** This option is incorrect as it does not accurately represent the current understanding of Ewing's sarcoma's cellular origin.
**Option C:** This option is also incorrect as the cell of origin for Ewing's sarcoma is not definitively identified as this cell type.

**Clinical Pearl / High-Yield Fact**
Ewing's sarcoma is highly malignant and requires prompt treatment, usually involving a combination of surgery, chemotherapy, and radiation therapy. The **5-year survival rate** has improved significantly with current therapies, making early diagnosis crucial.

**Correct Answer:** D. Neuroectodermal cells.