[SC悬赏令] 向大神牛牛们请教一道语法题

1.      In a blow to those who still harbored the illusion that E-mailexchanges are private, a watchdog group recently uncovered a trick for enablingan interloper to rig an E-mail message so that this person will be privy to anycomments that a recipient had added as the message is forwarded to othersor sent back and forth.  
A who still harbored the illusion that E-mail exchanges are private, a watchdoggroup recently uncovered a trick for enabling an interloper to rig an E-mailmessage so that this person will be privy to any comments that a recipient hadadded
B who had still been harboring the illusion that E-mail exchanges are private, awatchdog group recently uncovered a trick for enabling an interloper to rig anE-mail message so that this person was privy to any comments that a recipientmight have added
C who still were harboring the illusion that E-mail exchanges are private, awatchdog group recently uncovered a trick enabling an interloper to rig anE-mail message so that this person is privy to any comments that a recipientwould add
D still harboring the illusion that E-mail exchanges are private, a watchdoggroup recently uncovered a trick that enables an interloper to rig an E-mailmessage so that this person will be privy to any comments that a recipientmight add
E still harboring the illusion that E-mail exchanges had been private, awatchdog group recently uncovered a trick that will enable an interloper to rigan E-mail message so that this person was privy to any comments that arecipient might add
这道题目正确答案选择D,但我选的是C，其实我也不明白C选项，只不过我觉得who作为从句引导词是不能省略的吧。。。。。整个句子没看明白，希望大神帮我分析一下~谢谢啦！！！