**Core Concept**
Vitamin A is an essential nutrient for infants, playing a critical role in maintaining healthy vision, immune function, and epithelial integrity. The recommended daily dietary allowance (RDA) of vitamin A varies by age and is crucial for preventing deficiency-related disorders.

**Why the Correct Answer is Right**
The RDA of vitamin A for infants is based on their growth rate and body weight. Infants require a sufficient amount of preformed vitamin A (retinol) from animal sources or beta-carotene from plant sources to support their development. The adequate intake of vitamin A during infancy is crucial for the maturation of the retina and the maintenance of a healthy mucosal barrier.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect because it may not reflect the actual RDA for infants. The RDA of vitamin A varies by age, and infants have specific requirements.

**Option B:** This option may be incorrect because it may not be based on the latest nutritional guidelines. The RDA of vitamin A is subject to revision as new evidence emerges.

**Option C:** This option may be incorrect because it may be the RDA for a different age group or population. The RDA of vitamin A can vary depending on factors such as age, sex, and nutritional status.

**Clinical Pearl / High-Yield Fact**
The RDA of vitamin A for infants is crucial for preventing deficiency-related disorders such as night blindness and impaired immune function. It is essential for pediatricians and healthcare providers to ensure that infants receive adequate vitamin A supplementation, especially in areas where dietary sources are limited.

**Correct Answer:** 400-500 micrograms (mcg) of retinol activity equivalents (RAE) per day.