A

题目分析：句意：我的老师真好。我从来忘不了他给我的帮助。这里使用了词组：do sb a favor “给予某人帮助”。后面是一个that引导的定语从句，它的先行词就是favor，然后是that在从句he has done me中当宾语，可以省略。原句是I'll never forget the favor that he has done me. B．kindness 善良，C．help 帮助， D．benefit利益，所以选A。