What is the primary role of bile in the digestive system?

The primary role of bile in the digestive system is to break down fats. Bile is a digestive fluid produced by the liver and stored in the gallbladder. When fatty foods enter the small intestine, bile is released to emulsify these fats, which means it breaks them down into smaller droplets. This emulsification increases the surface area of fats, making it easier for digestive enzymes to access and further digest them into fatty acids and glycerol. This process is crucial for the proper absorption of fats and fat-soluble vitamins in the intestines.

The other options, while related to various functions in the body, do not represent the primary function of bile. Storing vitamins, absorbing nutrients, and producing insulin involve different organs and processes in the body that are separate from the action of bile in fat digestion.