**Core Concept**
Retinoblastoma is a malignant tumor of the retina, typically affecting children. It's a type of intraocular cancer that requires prompt diagnosis and treatment. Retinoblastoma can be hereditary or non-hereditary, and its clinical presentation and management vary accordingly.

**Why the Correct Answer is Right**
Retinoblastoma often presents with leukocoria, also known as "cat's eye reflex," which is the most common clinical presentation. Leukocoria is caused by the reflection of light off the tumor within the eye. The disease can be unilateral or bilateral, and about 40% of cases are associated with a family history of retinoblastoma, indicating a hereditary component. While enucleation (surgical removal of the eye) is a treatment option, it's not the only treatment, and the most common age group affected is indeed 1-2 years.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because strabismus (crossed eyes) and vision loss are also common presentations of retinoblastoma, although leukocoria is the most common.
**Option B:** Incorrect because retinoblastoma can be bilateral in about 25-30% of cases.
**Option D:** Incorrect because other treatment options include chemotherapy, radiation therapy, and cryotherapy, in addition to enucleation.
**Option E:** Incorrect because the most common age group affected is indeed 1-2 years, but retinoblastoma can also occur in older children.

**Clinical Pearl / High-Yield Fact**
Retinoblastoma is a classic example of a hereditary cancer syndrome, and patients with a family history should be screened for the disease. The VHL (von Hippel-Lindau) gene, RB1 (retinoblastoma 1) gene, and TP53 (tumor protein p53) gene are some of the genes associated with retinoblastoma.

**Correct Answer:** C. May have family history