http://grammar.ccc.commnet.edu/grammar/plurals.htm#collective_nouns
Let me know what you think.
In American English, a collective noun used as a unit takes _____ verbs and pronouns.
singular
plural
2 answers
Here's the big clue: "used as a unit"
"a unit" = singular; therefore, singular verbs and pronouns
"a unit" = singular; therefore, singular verbs and pronouns