**Core Concept**
Retinoblastoma is a malignant tumor of the retina, primarily affecting children under the age of 5. It arises from the retinal cells, specifically the photoreceptors, and is characterized by its rapid growth and potential for metastasis. The pathogenesis of retinoblastoma involves mutations in the RB1 gene, which regulates cell cycle progression.

**Why the Correct Answer is Right**
The correct answer is linked to the genetic predisposition of retinoblastoma. Mutations in the RB1 gene, a tumor suppressor gene, lead to uncontrolled cell proliferation and tumor formation. The RB1 gene product, pRb, inhibits the transcription of genes involved in cell cycle progression, including E2F. Loss of pRb function allows for the unchecked expression of these genes, promoting tumor growth.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because retinoblastoma is not primarily associated with viral infections. While viruses can cause retinal damage, retinoblastoma is a genetic disorder.

**Option B:**
This option is incorrect because neuroblastoma is a different type of tumor, originating from the neural crest cells. It is not directly associated with the genetic mutations that cause retinoblastoma.

**Option C:**
This option is incorrect because retinoblastoma is not typically associated with radiation exposure. While radiation can cause retinal damage, it is not a primary risk factor for developing retinoblastoma.

**Clinical Pearl / High-Yield Fact**
Retinoblastoma often presents with leukocoria (white reflex), a characteristic sign of the disease. This occurs due to the tumor's growth into the vitreous humor, causing light to be scattered and appearing white.