[This is a fast-access FAQ excerpt.]
Use of a plural verb after a singular noun denoting a group of
persons (known as a noun of multitude) is commoner in the U.K. than
in the U.S. Fowler wrote: "The Cabinet is divided is better,
because in the order of thought a whole must precede division; and
The Cabinet are agreed is better, because it takes two or more
to agree."
[See further comments on group names.]