A, B, C, and D discussed how their classmates completed their homework. A said: All the students in the class have finished their homework. B said: If Xiao Li finishes his homework, then Xiao Zhao hasn't finished his homework. C Say: Xiao Li finished his homework. D said: Someone in the class did not finish his homework.
What A said is wrong, Xiao Zhao didn't finish his homework can be derived.