**Core Concept**
In pediatric ophthalmology, cycloplegic agents are used to temporarily paralyze accommodation, allowing for accurate measurement of refractive errors in children. The preferred cycloplegic drug in infants and young children must be safe, effective, and have minimal systemic side effects.

**Why the Correct Answer is Right**
The correct answer is Cyclopentolate. Cyclopentolate is a non-selective muscarinic receptor antagonist that effectively paralyzes accommodation in children. It is widely used in pediatric ophthalmology due to its rapid onset of action and short duration of effect, making it ideal for refraction in young children. Cyclopentolate is available in various concentrations, including 0.5% and 1%, and can be administered topically.

**Why Each Wrong Option is Incorrect**
**Option A:** Atropine, although a potent cycloplegic agent, is not the preferred choice in infants due to its prolonged duration of action, which can lead to dry mouth, blurred vision, and other systemic side effects.
**Option B:** Homatropine is another cycloplegic agent, but it has a slower onset of action and shorter duration of effect compared to cyclopentolate, making it less suitable for refraction in young children.
**Option C:** Tropicamide is a short-acting cycloplegic agent, but it is not as effective as cyclopentolate in paralyzing accommodation in children, and its shorter duration of action may require multiple applications.

**Clinical Pearl / High-Yield Fact**
When choosing a cycloplegic agent in pediatric ophthalmology, consider the age of the child, the desired duration of action, and potential systemic side effects. Cyclopentolate is a safe and effective choice in young children, but atropine may be preferred in infants under 6 months of age due to its longer duration of action.

**Correct Answer: C. Cyclopentolate**