According to the passage the term "legal principles" as used by Dworkin refers to A. a comprehensive code of ethics that governs the behavior of professionals in the legal system B. explicit analyses of the terms used in legal rules indicating what meanings the terms do and do not cover C. legal doctrines that underlie and guide the use of accepted legal rules D. legal rules that have not yet passed through the entire legislative procedure necessary for them to become law E. the body of legal decisions regarding cases that required judicial discretion for their resolution