The answer is E. Stain.
A, B, C, and D are all actions that can be used to clean something. A stain, on the other hand, is a mark that is difficult to remove.
Sweeping is the act of brushing dirt or debris off of a floor or other surface with a broom. Wiping is the act of cleaning a surface with a cloth or paper towel. Scrubbing is the act of cleaning a surface with a brush or other abrasive tool. Washing is the act of cleaning a surface with water and soap.
A stain is a mark that is difficult to remove. It can be caused by a variety of things, such as food, drink, blood, or ink. Stains can be removed with a variety of methods, depending on the type of stain and the surface it is on.