## Core Concept
The Recommended Dietary Allowance (RDA) is a standard nutritional guideline that represents the average daily intake level of a nutrient that meets the nutrient requirements of 97-98% of healthy individuals in a specific life stage and gender group. RDAs are part of the Dietary Reference Intake (DRI) system established by the National Academies of Sciences, Engineering, and Medicine.

## Why the Correct Answer is Right
The RDA is set to cover the nutrient requirements of 97-98% of healthy individuals in a specific life stage and gender group. This means that the RDA aims to provide a buffer above the average requirement to ensure that most people's needs are met, making it a suitable standard for planning diets for individuals.

## Why Each Wrong Option is Incorrect
**Option A:** This option is incorrect because it does not accurately reflect the percentage of the population that the RDA is designed to cover.
**Option B:** This option is incorrect for similar reasons as Option A; it does not accurately represent the coverage provided by the RDA.
**Option D:** This option suggests a much lower coverage than what the RDA is intended to provide.

## Clinical Pearl / High-Yield Fact
A key point to remember is that RDAs are used for planning and assessing nutrient intake for individuals, and they are based on the Estimated Average Requirement (EAR). If the RDA is met, it is assumed that the nutrient requirements are being met for virtually all (97-98%) healthy individuals.

## Correct Answer: C. 97-98%