**Core Concept**
Carbohydrates are a major component of many biological molecules, and their classification is crucial for understanding their functions and roles in the body. Compounds with large amounts of carbohydrate and small amounts of protein are typically classified as polysaccharides, which are complex carbohydrates composed of multiple sugar units.

**Why the Correct Answer is Right**
Polysaccharides, such as starch, glycogen, and cellulose, are formed by the condensation of many monosaccharide units. They serve various functions in the body, including energy storage (glycogen) and structural support (cellulose in plant cell walls). The high carbohydrate content and low protein content of polysaccharides distinguish them from other types of biomolecules.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as nucleic acids (DNA, RNA) have high nitrogen content due to the presence of purine and pyrimidine bases, making them distinct from polysaccharides.
**Option B:** Incorrect, as lipids (fats, oils) are predominantly composed of carbon, hydrogen, and oxygen, but lack the large carbohydrate content characteristic of polysaccharides.
**Option C:** Incorrect, as amino acids and proteins contain a significant amount of nitrogen and have a fixed ratio of carbon, hydrogen, oxygen, and nitrogen atoms, which is not typical of polysaccharides.

**Clinical Pearl / High-Yield Fact**
Polysaccharides, particularly glycogen, play a crucial role in maintaining blood glucose levels and providing energy for the body. A deficiency in glycogen synthase, the enzyme responsible for glycogen synthesis, can lead to glycogen storage diseases.

**Correct Answer: D. Polysaccharides**