56 year old man. 3 weeks RUQ pain and 15 lb weight loss. 1 week of jaundice and dark urine. History of ulcerative colitis. Normal vital signs. Appears cachetic. AST and ALT and Alk phos elevated. Elevated total bilirubin. CT reveals dilated intrahepatic ducts and a normal sized common bile duct. CEA and CA 19-9 elevated. serum AFP normal. Most likely?
A. Cholangiocarcinoma
B. Choledocholithiasis
C. Hepatocellular cancer
D. Metastatic colon cancer
E. Pancreatic cancer