The walls look clean.They____?

问题描述:

The walls look clean.They____?
A.needn't painted B.don't need painted
c.needn't to be painted D.don't need painting
请说明理由

D.don't need painting
need作行为动词是don't need to do
need作情态动词是needn't do
need doing =need to be done
因为是被动,所以need painting