ANSWER: Secretion of less saliva in the mouth will mainly affect the conversion of starch into simple sugars. Saliva contains the enzyme salivary amylase (ptyalin), which breaks down starch into maltose and other simple sugars during chewing. If saliva production is reduced, this enzymatic action slows down, leading to incomplete digestion of starch in the mouth. Proteins, fats, and sugars are digested in later parts of the alimentary canal, so their conversion is not significantly affected by saliva deficiency. Answer: (C).