Which use of edges is most effective for emphasizing the main subject?

Correct answer: Use clear edges on important parts of the subject and softer edges elsewhere

The governing concept is emphasis through selective edge control. Clear, sharper edges in important parts of the subject attract the eye, while softer edges elsewhere reduce competition and preserve visual hierarchy. Thus option B is most effective. Blurring the subject hides it, identical edges give every area equal importance, and a black outline may look artificial rather than creating convincing emphasis.