An underwater hotel has opened in Africa，with its rooms＿on the bottom of a three－level floating building．

A．to sit

B．sit

C．sitting

D．sat

患者男52岁，皮肤、巩膜黄染进行性加重，上腹部胀痛不适1个月余，B超检查，胰管扩张，如图所示，根据超声声像图，诊断为（）

A.胆总管下段癌

B.肝门部胆管癌

C.壶腹部癌

D.胆总管下段结石

E.胰头癌