**Core Concept**
The question is testing knowledge of congenital cataracts, a type of lens opacity present at birth. Congenital cataracts can be caused by genetic mutations, intrauterine infections, or environmental factors.

**Why the Correct Answer is Right**
The most common type of congenital cataract is the **snowflake cataract**, which is characterized by a scattered, snowflake-like pattern of opacities within the lens. This type of cataract is often bilateral and can be associated with other systemic conditions, such as Down syndrome or congenital rubella syndrome. The snowflake cataract is thought to result from a disruption in lens development during embryogenesis.

**Why Each Wrong Option is Incorrect**
**Option A:** **Zonular cataract** is a type of congenital cataract that affects the zonular fibers, but it is not the most common type.
**Option B:** **Posterior polar cataract** is a type of congenital cataract that affects the posterior capsule of the lens, but it is relatively rare.
**Option C:** **Lamellar cataract** is a type of congenital cataract that affects the lens cortex, but it is not the most common type.

**Clinical Pearl / High-Yield Fact**
The snowflake cataract is often associated with other systemic conditions, making it an important consideration in pediatric patients with congenital cataracts.

**Correct Answer: C. Snowflake cataract.**