**Core Concept**
The **sun-ray appearance** is a radiological finding that refers to a pattern of bony spicules extending outward from a bone lesion, typically seen in **osteosarcoma**. This appearance is due to the periosteal reaction, where the **periosteum** forms new bone in response to the underlying lesion.

**Why the Correct Answer is Right**
Since the correct answer is not provided, let's discuss the general approach to this question. The sun-ray appearance can be seen in other conditions that cause a periosteal reaction, such as **Ewing's sarcoma** or **osteomyelitis**.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option provided, it's difficult to comment on its accuracy.
**Option B:** Similarly, without the option, we cannot assess its correctness.
**Option C:** The same applies to this option.
**Option D:** Again, the option is not provided for evaluation.

**Clinical Pearl / High-Yield Fact**
The **sun-ray appearance** is a key radiological feature that suggests an aggressive bone lesion, often requiring further investigation, such as biopsy, to determine the underlying cause.

**Correct Answer:** Not provided in the query.