The classroom wants ( ).look,it's so dirty.A clealing B being cleaned C to clean D cleans

问题描述:

The classroom wants ( ).look,it's so dirty.A clealing B being cleaned C to clean D cleans
选哪一个?我觉得应该是:to be cleaned,但答案是A,请问是为什么?谢谢
没别的原因?能不能说具体一点

want cleaning= want to be cleaned