I believe it is B because for a monopoly it has no close substitute and is protected by a barrier that prevents other firms from selling that good or service
Explanation:
Turn off the faucet while brushing your teeth.
Only run the washing machine and dishwasher when you have a full load.
Monitor your water usage on your water bill
The superstition that I've heard of is that if you look into a mirror at midnight on Halloween you might see your future spouse (but there might be others too).
United states is the answer I think.
