According to the meaning of the question, it is discussed in two situations:

(1), one class receives 2 people, and the other two classes each receive 1 person. The allocation scheme is C3 1? C42？ A22=36 species,

(2), one class does not accept, and the other two classes each accept 2 students. The allocation scheme is C3 1? C42= 18 species;

So there are 36+ 18=54 different distribution schemes to meet the meaning of the question.

Therefore, choose: B.