* Confused between whom and who

[QuickSilver]

2. All the firms have a panel of brokers through whom they transact deals and
build databases.
(a) brokers through whom they
(b) brokers, through whom they
(c) brokers through which they
(d) brokers, through which they


Here the second sentence refers to the 'panel of brokers' so does that
mean it should be " through which " or " through whom " ?

panel is a thing so shud it not be refered as "which" ? ignoring the middleman of.

... though at first I chose 'a' now I am confused......................................
_________________
Thanks
Senthil

[Jack]

Yes thorugh which is certainly correct !

I go for C .

whats the official Answer ?

[JonathanSchneider]

Please cite the original source of this question. Otherwise we will be forced to delete it. Thank you.