Which organ produces bile and stores it in the gallbladder?

The liver is the organ responsible for producing bile, which is essential for the digestion and emulsification of fats in the small intestine. Once the liver produces bile, it is stored in the gallbladder, where it can be concentrated and released into the digestive tract when needed, particularly after the consumption of fatty foods. This process is crucial for the body’s ability to absorb dietary fats and fat-soluble vitamins.

While the other organs mentioned have important functions, they do not play a role in bile production or storage. The kidneys are primarily involved in filtering blood and producing urine, the pancreas has a role in producing digestive enzymes and insulin, and the spleen is involved in immune functions and blood filtration. Thus, the liver's unique role in bile production and storage distinguishes it as the correct answer.