**Core Concept**
Chitin is a polysaccharide composed of a long chain of linked N-acetylglucosamine units. It is the primary structural component of exoskeletons in arthropods, such as insects and crustaceans, and is also found in the cell walls of fungi.

**Why the Correct Answer is Right**
The correct answer is a derivative of glucose, specifically N-acetylglucosamine. This is because chitin is synthesized from UDP-N-acetylglucosamine, a molecule derived from glucose, through the action of the enzyme chitin synthase. The resulting chitin polymer is then secreted from the cell and assembled into the exoskeleton or cell wall.

**Why Each Wrong Option is Incorrect**
**Option A:** Glycoprotein - Chitin is a polysaccharide, not a glycoprotein, which is a type of protein that contains carbohydrate chains.
**Option B:** Peptide - Chitin is a polysaccharide, not a peptide, which is a short chain of amino acids.
**Option C:** Polysaccharide - While this option is partially correct, it is too general and does not specify the type of polysaccharide that chitin is.

**Clinical Pearl / High-Yield Fact**
Chitin is a key component of the exoskeletons of arthropods, and its degradation is a critical step in the breakdown of these structures, allowing for the release of nutrients and the recycling of materials.

**Correct Answer: C. N-acetylglucosamine.**