Which set comprises the major GI tract sphincters typically considered in endoscopy?

Which set comprises the major GI tract sphincters typically considered in endoscopy?

• A. Lower esophageal sphincter, pyloric sphincter, ileocecal valve, anal sphincter.
• B. Upper esophageal sphincter, lower esophageal sphincter, pyloric sphincter, ileocecal valve.
• C. Cardia, pyloric valve, sphincter of Oddi, anal sphincter.
• D. Upper esophageal sphincter, external anal sphincter, ileocecal valve, pyloric sphincter.

Answer: (B)