The supporters of either party have rationalized their own opinion in terms of argument.【同义替换】

A. with regard to

B. in addition to

C. in addition to

D. as opposed to

【答案解析】本题正确选项A。【译文】这两个党派中任何一派的支持者都在争论中理性地阐述了自己的观点。【解析】在四个选项中，with regard to“关于”；in constant to“在……当中”；in addition to“另外”；as opposed to“与……相反”；in terms of意为“关于”。因此，依据题意在四个选项中最符合题意的选项是A。