Randy rents a house from Charles for $$800$ a month. However, for the current year, Charles reduced the rent to $$400$ a month. In exchange, Randy has agreed to build a deck onto the house. The deck is worth $$4,500,$ but Randy only spent $$2,800$ on materials. How much rental income must Charles recognize in the current year?

Question $16$ options:

$$7,600$

$$9,300$

$$4,800$

$$9,600$