问一道简单的题

好运9月9

Federal authorities involved in the investigation have found the local witnesses are difficult to locate, reticent, and are suspicious of stranters.
A the local witnesses are difficult to locate, reticent, and are
B local witnesses to be difficult to locate, reticent, and are
C that local witnesses are difficult to locare, reticent, and
D local witnesses are difficult to locate and reticentm and they are
E that local witnesses are difficult to locate and reticent, and they are

这题选C  我想问的是c选项的reticent是动词啊，不是应该加上个and 才行么  所以我选E了。。。  菜鸟求指教！

gracefighting

E的they 有歧义啊，可以指 witnesses 也可以指 federal authorities

C的并列从are后面开始 ， difficult, reticent, suspicious 三个形容词并列， reticent 是   有所保留的    的意思