John is thinking of buying a duplex. His monthly expenses will be $1,000 for the mortgage, $550 for taxes, and $350 for insurance. He also needs to pay an annual association fee of $900. If he can rent out one-half of the unit for $1,800 per month, how much will he make or lose per month?

	a.	He will make $250.
	b.	He will lose $100.
	c.	He will make $800.
	d.	He will lose $1,000.