Concept:Enzymes are biological catalysts that speed up chemical reactions, and the vast majority of them are made of protein.Explanation:Our body naturally produces enzymes to perform essential tasks. These include building muscle, destroying toxins, and breaking down food during digestion. The three main types of digestive enzymes are: Amylase, which breaks down starches and carbohydrates into sugars; Lipase, which breaks down fats and oils into glycerol and fatty acids; and Protease, which breaks down proteins into amino acids. Since most enzymes are proteins, their structure and function are affected by temperature and pH changes. Proteins are known as the building blocks of the body because they build and repair cells and tissues. Good sources of protein include milk, eggs, meat, fish, nuts, pulses, and soyabean. Protein deficiency can lead to diseases like Kwashiorkor and Marasmus in children.Answer:D. proteins