[单选题]In a business letter, _________ refers to the full address and zip code of the sender.zkw答案窝(daanwo.com)-大学生作业答案及考资分享平台 Aletterheadzkw答案窝(daanwo.com)-大学生作业答案及考资分享平台 Binside addresszkw答案窝(daanwo.com)-大学生作业答案及考资分享平台 Ccomplimentary closezkw答案窝(daanwo.com)-大学生作业答案及考资分享平台 Dsalutation