A is the answer: It forces the boys to let go of some of society's conventions.
I know because I just took the test.
The answer should be an object of a verb. The bold words are neither a proposition(which is a word that expresses a relation to another word, like "after" or "next to") or the subject. The subject in this case would be the city of Washington.
Answer: Hint : is not Properties!!!
Explanation: Because sports property, whether it is an arena, a team or event has assets: its audience, advertising and promotional opportunities, signage, tickets, promotions, programs, premier seating, hospitality, profile in your community, etc., all which have a potential value to a sponsor.