ANATOMY

Detailed explanation-1: -The correct option is A liver. The digestive system of humans consists of: The alimentary canal includes the buccal cavity, oesophagus, stomach, small intestine large intestine, rectum and anus. Whereas liver is an accessory glands which plays supportive role in the process of digestion.

Detailed explanation-2: -The gastrointestinal system includes the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and anus. It also includes the salivary glands, liver, gallbladder, and pancreas, which make digestive juices and enzymes that help the body digest food and liquids.

Detailed explanation-3: -Upper GI (liver, pancreas, biliary tract and oesophago-gastric)