—Oil is everywhere in this store so you know smoking is forbidden here.—I’m sorry.A. can

问题补充：

—Oil is everywhere in this store, so you know smoking is forbidden here.

—I’m sorry.

A. can B. may C. must

答案：

解析：本题的含义是这儿到处都是油，所以抽烟必须被禁止，must表示必须的意思，故本题选C。