Correct answer: D). Algal cells have a cell wall made of chitin, while plant cell walls are made of cellulose.
Algae and plants are similar as both of them produce their own food by the process of photosynthesis. The main difference is found in their complexity.
The cell wall of the plants is made of cellulose, hemicellulose and pectin, and polysaccharides, while the cell wall of algae is made up of chitin, which is a polysaccharide derived from glucose.