The main distinguishing feature of literature is often considered to be:

B. is relevant to life

Literature, in its various forms, explores and reflects upon the complexities of human experience, emotions, and societal issues. While literature can certainly include fictional elements (making option D partially correct), it may also include true events as in the case of non-fictions. Its significance often lies in its ability to offer insights into the human condition and provide readers with a deeper understanding of life, relationships, and the world around them.