The Olympic Games in the year 2012_______in London of Britai

The Olympic Games in the year 2012_______in London of Britain,which ______known to us all.
A.is to hold;are B.is to be held;was C.are to hold;is D.are to be held;is
我想知道为什么不选B而选D，the Olympia games in the year 2012不是单数吗？为什么用are？