A metaphor can be defined as a figure of speech typically used in literature to describe an action or object in a non-literal way. It's most commonly used to emphasize a point or make a comparison between two objects. The correct answer is option D: " The beauty of nature, a delicious treat", because, the beauty of anything (nature, a person or feeling) cannot be literally "eaten" therefore, it cannot be a treat (delicious or otherwise). The other options are discarded as correct answers because they are actions/emotions that can be done/felt literally.