Poem dissuades thief

People may invest in fancy alarm systems or locks to keep thieves out, but one house owner's poem was even more effective than a lock in dissuading a thief in Shijiazhuang. When a thief broke into a house in a village there, he not only stole nothing, but even left a hundred yuan and a note on the table. The note said, "This thief entered and intended to steal. But I saw the words on your wall and changed my mind. Here's a hundred. Goodbye." The words the thief mentioned referred to the calligraphy the house owner practiced to encourage himself to stand on his own feet even in old age. The house owner said he would like to meet the thief to have a chat about life.

What did the thief steal?

A. A 100 yuan note

B. A calligraphy on the wall

C. Nothing

（中国日报网英语点津 Helen 编辑）