what is the answer
There are students in a certain class who do good deeds without leaving their name. Four teachers, A, B, C, and D, expressed their opinions to the four students on the board. A said: "If Zhang San did not do this, it must have been done by Zhao Liu." B said: "If Zhang San did this, then Li Si or Wang Wu would also do it." C said: "If Li Si did not do this, then Wang Wu would not do it either; Zhao Liu would not be such a person." Ding said: "Zhang San must have done this, and neither Li Si nor Wang Wu would do it." It was later learned that only one of the four teachers' opinions was right. Based on this, it can be inferred that the student who does good deeds is ( ) A. Zhang San B. Li Si C. Wang Wu D. Zhao Liu Everyone is welcome to answer!
