The author refers to the Council of Basel primarily in order to A. provide an example of the type of action needed to establish professional standards for canon lawyers B. contrast the reactions of English church authorities with the reactions of other bodies to violations of professional standards by canon lawyers C. bolster the argument that violations of professional standards by canon lawyers did take place D. explain how rules of conduct for canon lawyers were established E. describe the development of a disciplinary system to enforce professional standards among canon lawyers