Tania buys an apartment in Vancouver for $650,000; $150,000 down payment and $500,000 mortgage with 2% annual interest cost. She rents the place for $2,400 per month. The total monthly expenses, excluding the interest cost, for that apartment is $800. How much will be her ROI at the end of the year? O a. 12.8% Ob. 6.13% O c. 10.8% O d. 6.31%