**Core Concept**
Retinoblastoma is a malignant tumor of the retina, primarily affecting children. The disease can be unilateral or bilateral, with bilateral cases often associated with a genetic predisposition. The bilateral form is typically linked to mutations in the RB1 tumor suppressor gene.

**Why the Correct Answer is Right**
Bilateral retinoblastoma is often inherited in an autosomal dominant pattern, resulting from mutations in the RB1 gene. This gene plays a crucial role in regulating cell cycle progression and preventing uncontrolled cell growth. In bilateral cases, the mutation can be inherited from an affected parent or occur spontaneously. The presence of bilateral retinoblastoma significantly increases the risk of developing other cancers, such as osteosarcoma and melanoma.

**Why Each Wrong Option is Incorrect**
**Option A:** Unilateral retinoblastoma is not typically associated with a genetic predisposition and is more likely to occur sporadically.
**Option B:** Trilateral retinoblastoma refers to a rare variant of the disease involving the pineal gland in addition to the eyes, but it is not the correct answer in this context.
**Option C:** Familial retinoblastoma is a broader term encompassing both bilateral and unilateral cases with a genetic component, but it does not specifically refer to the bilateral form.

**Clinical Pearl / High-Yield Fact**
In cases of bilateral retinoblastoma, it is essential to screen family members for the RB1 gene mutation to identify individuals at risk of developing the disease.

**Correct Answer: B. Trilateral retinoblastoma is not the correct answer in this context. In fact, the answer is actually C. Trilateral retinoblastoma is a rare variant with involvement of the pineal gland, but the actual answer is more closely related to familial retinoblastoma. I'll correct it.**

**Correct Answer: C. Familial retinoblastoma encompasses both bilateral and unilateral cases with a genetic component.**