In the following regression model $=30,000+2$x with given sales $($in $$1000)$ and marketing expenses $($in $$),$ how would you interpret the slope of the equation?

A$.$ An increase of $$1\mathrm{.}0$ in marketing expenses is associated with an increase of $$2\mathrm{.}0$ in sales.

B$.$ An increase of $$1\mathrm{.}0$ in marketing expenses is associated with an increase of $$1000$ in sales.

C$.$ An increase of $$1\mathrm{.}0$ in marketing expenses is associated with an increase of $$2,000$ in sales.

D$.$ An increase of $$1\mathrm{.}0$ in marketing expenses is associated with a decrease of $$2,000$ in sales.