Oesophageal varices are caused by which ONE of the following?

The answer is B. Portal hypertension (usually caused by cirrhosis) results from interference with the hepatic micro-circulation such that vessels in the portal-systemic anastomotic system become engorged and develop varicosities. This occurs most spectacularly in the oesophagus, and rupture of these veins is a common cause of death in alcoholics.