- The correct answer is Chitin because fungi have cell walls made primarily of chitin, a strong, flexible polysaccharide.
- In contrast, plant cell walls are mainly composed of cellulose.
- This difference in cell wall composition is a fundamental characteristic that distinguishes fungi from plants.
- Neither lignin nor peptidoglycan are major components of fungal cell walls; lignin is associated with plant secondary walls, while peptidoglycan is specific to bacterial cell walls.

Reference: Robbins Basic Pathology, 10th Edition, Chapter 1, Cell Biology