**Core Concept**
Retinoblastoma is a malignant tumor of the retina, primarily affecting young children. Bilateral (B/L) multifocal retinoblastoma indicates the presence of multiple tumors in both eyes, necessitating a comprehensive treatment plan to preserve vision and prevent tumor spread.

**Why the Correct Answer is Right**
In cases of bilateral multifocal retinoblastoma, enucleation (removal of the affected eye) is often considered a primary treatment option to prevent tumor spread and preserve life. This approach is particularly crucial when the tumors are advanced, and vision salvage is not feasible. The correct answer, **chemotherapy and radiotherapy**, is often used in conjunction with enucleation or as an alternative treatment option, especially in cases where vision preservation is a priority.

**Why Each Wrong Option is Incorrect**
**Option A:** Enucleation alone may not be sufficient for bilateral multifocal retinoblastoma, as it may not address the underlying disease process and prevent potential spread to the contralateral eye.
**Option B:** Laser photocoagulation and cryotherapy are local treatments used for small, unilateral retinoblastomas, but they are not sufficient for managing bilateral multifocal disease.
**Option C:** Systemic chemotherapy is an essential component of retinoblastoma treatment, but it is not the primary approach for managing bilateral multifocal disease; rather, it is often used in conjunction with other treatments.

**Clinical Pearl / High-Yield Fact**
Retinoblastoma is the most common primary intraocular malignancy in children, with a peak incidence between 1-3 years of age. Early detection and prompt treatment are critical to prevent tumor spread and preserve vision.

**Correct Answer: C. Chemotherapy and radiotherapy. Chemotherapy and radiotherapy.**