Fructose is often regarded as the sweetest sugar among the options provided. It is a natural sugar found in fruits, honey, and some vegetables. Fructose is sweeter than glucose, sucrose (which is a combination of glucose and fructose), and maltose. Due to its high sweetness level, fructose is commonly used as a sweetener in various food products and beverages.

The main function of epithelial tissue is:

(C) Defense

Explanation:

Epithelial tissue serves as a protective covering for the body and its organs. It acts as a barrier that helps prevent the entry of pathogens and other harmful substances. Epithelial cells are tightly packed and form continuous sheets, providing a protective layer on the body surfaces, both internal and external. This protective function is essential for defending the body against infections and maintaining its integrity. Therefore, option (C) Defense is the correct answer.