The correct answer is A. Both A and R are individually true and R is the correct explanation of A.
The liver is a vital organ that performs many important functions in the body, including fat digestion. The liver produces two important fat digesting enzymes, bile salts and lipase. Bile salts help to break down large fat molecules into smaller ones that can be absorbed by the body. Lipase is an enzyme that helps to break down triglycerides, a type of fat, into fatty acids and glycerol.
Therefore, both A and R are individually true. Additionally, R is the correct explanation of A because it explains how the liver helps to digest fat.