In which condition would keeping a shape boundary soft be more suitable?

While showing mist, cloud, or smoke

A soft boundary is useful when an object does not have a sharp, clearly visible edge. Mist, clouds, and smoke blend gradually into the surrounding space, so a hard outline may look unnatural. A soft edge can be made with gentle shading, blurred marks, or a gradual change in value. The boundary is suggested rather than strongly drawn, which helps communicate an unclear or changing natural form.

Option A is correct because mist, clouds, and smoke usually have diffuse edges. Traffic signs, machine parts, and geometric logos generally need firm boundaries so their shape and information are easy to read. The choice depends on the subject and the visual effect required. Soft edges suggest atmosphere and softness, while hard edges suggest precision and clear separation.

This is a Class 9 Art Education question. Chapter: Elements of Art. Topic: Shape.