Question

which of the following can increase levels of direct bilirubin?
gallstones
tumor at the head of the pancreas
inflammation of the bile duct
all of the above

Explanation:

Gallstones can obstruct the bile - duct, a tumor at the head of the pancreas can compress the bile - duct, and inflammation of the bile duct can also cause obstruction. All these can lead to impaired bile flow and increased levels of direct bilirubin.

Answer:

D. All of the above