—I left my handbag on the train, but luckily someone gave it to a railway official.

—How unbelievable to get it back! I mean, someone ______ it.

A．will have stolen

B．might have stolen

C．should have stolen

D．must have stolen

《边城》叙述了怎样一个故事？表现了作者什么样的人生追求？