OG2018 VERBAL 234疑问

Power2Bowen

A recent court decision has qualified a 1998 ruling that workers cannot be laid off if they have been given reason to believe that their jobs will be safe, provided that their performance remains satisfactory.

(A) if they have been given reason to believe that their jobs will
(B) if they are given reason for believing that their jobs would still
(C) having been given reason for believing that their jobs would
(D) having been given reason to believe their jobs to
(E) given reason to believe that their jobs will still





答案是A，错选了B。
求教除了would/will，reason to believe 和 reason for believing的考点。
OG说B中不能用are，不是很明白。求大神指导一下。
还有，希望大神顺便翻译一下这个正确的句子，小弟不才，翻来覆去，没有看明白。。。