A 67-year-old man with a 40 pack-year smoking history presents with progressive painless jaundice, weight loss, and epigastric discomfort over 8 weeks. Vital signs: BP 138/82, HR 92, RR 16, Temp 37.2°C, SpO2 98%. Physical examination reveals a palpable nontender gallbladder and no abdominal pain. Recent laboratory studies show elevated conjugated bilirubin at 8.2 mg/dL and alkaline phosphatase 320 U/L. He recently experienced migratory thrombophlebitis. Which of the following is the most likely diagnosis?

1. A)Pancreatic adenocarcinoma of the headGABARITO
2. B)Acute pancreatitis
3. C)Cholangiocarcinoma
4. D)Gallstone pancreatitis
5. E)Peptic ulcer disease