I am a bit confused on the following:
The newly elected baseball commissioner has asked that a federal arbitrator would mediate negotiations between representatives of the umpire's union which has threatened to go on strike, and the lawyers representing major league franchise owners.
I chose this response:
"that a federal arbitrator mediate negotiations between representatives of the umpire's union, which have threatened"
but it turns out that the answer is "HAS" instead of "HAVE"... why is the answer to make sure I am in agreement w/ UNION instead of REPRESENTATIVES?
Thanks so much in advance =)