Bile duct obstruction can be diagnosed by.. Bilirubin in urine

Bile duct obstruction can be diagnosed by:
a. AST
b. T. Bilirubin
c. Bilirubin in urine
d. Ester bilirubin

(c) Cholestatic hyperbilirubinemia is characterized by conjugated hyperbilirubinemia and hyperbilirubinuria (only the conjugated fraction appears in urine).