Concept:Fat digestion requires secretions from the pancreas and liver.
Explanation:I is the stomach, which secretes gastric juice and is not directly involved in fat digestion.
II is the pancreas; it secretes pancreatic lipase, the enzyme that breaks down fats into fatty acids and glycerol.
III is the liver; it produces bile, which emulsifies large fat globules into smaller droplets.
IV is the gall bladder; it only stores and concentrates bile produced by the liver, so it does not secrete its own digestive substances.
Thus, the parts that actually secrete substances involved in fat digestion are II and III.
Answer:C. II and III
