In autumn of 1935, when I was a young man, I was traveling in the north of Indian. One evening, before hunting in the forest all day, I was returning to the place which I had put up my tent. It was getting dark, but I was walking along a road. Suddenly I saw two eye glaring at me from among the trees. How could I do? Should I jump into the river to save my life? Then I look to the right. In the river there had a big crocodile waiting to welcome me with its mouth was wide opening.  

患者女性，56岁。吸烟史30年，刺激性咳嗽，痰中带血丝2周。胸片显示右肺门处阴影增大，纵隔增宽，上叶不张。

该患者为进一步明确诊断，下一步首选的检查是（）。

A.结素试验

B.肺CT检查

C.经胸壁穿刺活组织检查

D.痰培养加药敏试验

E.支气管镜检查