How does art make a cleanliness campaign effective?

Correct answer: By spreading messages through pictures, posters and slogans

The governing concept is the use of visual communication for public awareness. A cleanliness campaign becomes easier to notice and remember when it uses clear pictures, readable posters, attractive layouts and short slogans. These artistic elements can show the desired behaviour, such as using a bin, and can present the message to people who may not read a long explanation. Therefore, option D is correct. Hiding the message defeats communication, spreading garbage contradicts the campaign, and simply stopping people does not teach or persuade them. Effective campaign art combines a visible image with a concise, responsible message and places it where the intended audience can see it.