Final answer:
The main component of the cytosol is water. It makes up about 70 to 80 percent of the cytosol's composition and provides a medium for various cellular processes. Hence, option (4) is correct.
Step-by-step explanation:
The main component of the cytosol is water. Cytosol is the liquid part of the cytoplasm that surrounds the organelles within a cell. It is composed of about 70 to 80 percent water and serves as a medium in which a variety of cellular processes take place. This includes the presence of enzymes, which are proteins that catalyze biochemical reactions within the cell, and other dissolved substances like salts, amino acids, sugars, and fatty acids that are essential for the survival and function of the cell.
The high water content of the cytosol helps maintain the cell's volume and provides the appropriate environment for molecular interactions.