Final answer:
Cholecystokinin (CCK) is the hormone responsible for stimulating the gallbladder to release bile, aiding in the digestion of fats.
Step-by-step explanation:
The hormone that controls the release of bile from the gallbladder is cholecystokinin (CCK). CCK is released by intestinal cells in the mucosa of the small intestine when food, particularly fatty food, reaches this part of the digestive tract. The presence of CCK in the bloodstream stimulates the gallbladder to contract and release stored bile. This bile then assists in the digestion and absorption of fats by emulsifying triglycerides into smaller molecules that enzymes like pancreatic lipase can further break down.