**Core Concept**
The child requires vitamin A prophylaxis to prevent deficiency, which can lead to night blindness, impaired immune function, and even death. Vitamin A prophylaxis is especially crucial in children aged 6-59 months and pregnant women, but also recommended for children above 5 years in high-risk areas.

**Why the Correct Answer is Right**
The recommended dose for vitamin A prophylaxis in children above 5 years is 100,000 IU. The WHO recommends administering vitamin A orally, and for children above 5 years, the preferred route is oral administration. The dose is given once every 4-6 months in high-risk areas.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because the dose for children above 5 years is not 50,000 IU, but 100,000 IU.
**Option B:** This is incorrect because the recommended dose for children above 5 years is not 150,000 IU, but 100,000 IU.
**Option C:** This is incorrect because the recommended dose for children above 5 years is not 200,000 IU, but 100,000 IU.

**Clinical Pearl / High-Yield Fact**
It is essential to note that vitamin A should not be given to children with liver disease, kidney disease, or those taking anticoagulant medications. Also, the dose should not exceed 200,000 IU every 4-6 months.

**Correct Answer: D. 100,000 IU orally every 4-6 months.**