Which of the following is referred to as Courvoisier's sign?

Courvoisier's sign specifically refers to the phenomenon of jaundice accompanied by a palpable gallbladder. This clinical presentation is particularly significant because it suggests the presence of bile duct obstruction, commonly due to a tumor or stone causing the gallbladder to enlarge while bile accumulates. The gallbladder becomes distended and can be felt on physical examination, thereby distinguishing it from other causes of jaundice where the gallbladder may not be palpable.

In cases where there is an obstructed bile duct leading to increased pressure within the biliary system, the gallbladder may enlarge, leading to this sign. This finding has important diagnostic implications, directing further investigations towards potential obstructive causes, such as pancreatic cancer or choledocholithiasis, which require prompt management.

Other options, while they may present in various contexts of abdominal issues or diseases related to the liver or biliary system, do not specifically relate to Courvoisier's sign, making the recognition of the combination of jaundice and a palpable gallbladder crucial in clinical practice.