If the Marginal Cost for Big Ed's Used Car Emporium

If the marginal cost for Big Ed's Used Car Emporium to advertise one additional day each week on a local TV station is $1,500,then Big Ed's should advertize that additional day

A) only if the marginal benefit the company receives each week is greater than $1,500 plus an acceptable profit margin.
B) as long as the marginal benefit the company receives each week is just equal to or greater than $1,500.
C) as long as the weekly marginal cost does not rise.
D) until the marginal benefit the company receives reaches zero.