The correct option is A Pyloric sphincter
The broadest part of the alimentary canal is the stomach. Food enters here in the form of bolus. It is located in the left upper part of the abdomen. It is a J- shaped bag and is also known as the ‘gaster’. It has 4 regions namely cardiac, fundus (fundic region), body and pylorus (pyloric region). The opening of the stomach into duodenum is regulated by the pyloric sphincter.
The opening of the oesophagus into the stomach is regulated by the gastro-oesophageal sphincter.
The opening of the hepatopancreatic duct into the duodenum is guarded by the sphincter of Oddi.
The sphincter of Boyden is found surrounding the opening of the bile duct before it joins the pancreatic duct.