B-level writing demonstrates concrete support for claims, fine organization, and substantive thoughtfulness, but it is not rich in specific detail. B-level writing is free of grammatical problems. A represents a writing level of unusual polish and style, and often takes a surprising angle in developing a topic. A-level writing is rare, because it shows consistent excellence. A-level writing always surpasses assignment expectations.
C represents writing which probably satisfies all the requirements of an assignment.
However, such writing lacks sufficient, concrete support needed to illustrate its assertions or prove its point.