The correct option is A cellulose
Cellulose is the main substance present in the walls of plant cells, helping them to remain stiff and upright. Fatty acids are molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes. Xanthophylls are carotenoid pigments, responsible for imparting different colours in fruits, flowers and vegetables. Cellulose cannot be digested by humans, but are included in the diet as an important fibre supplement. Cell sap is a fluid found in the vacuoles of living plant cells.