The correct choice includes the spleen, kidneys, and pancreas, which are classified as solid abdominal organs. Solid organs are typically defined by their firm tissue structure, as opposed to hollow organs which contain contents such as fluid or food.
The spleen plays a crucial role in filtering blood and is responsible for the immune response. The kidneys are essential for filtering waste from the blood and regulating electrolyte balance. The pancreas, while known for its role in digestion and insulin production, is also a solid organ because of its dense tissue structure.
In contrast, the stomach and small intestine are hollow organs mainly designed for digestion and movement of contents. The gallbladder stores bile but does not have a solid structure. The large intestine is also hollow, involved in water absorption and waste processing. The urinary bladder, colon, and ureters are all hollow organs focusing on storage and transportation of fluids. Thus, the selection of spleen, kidneys, and pancreas accurately represents the solid organs within the abdominal cavity.