If Demand Is Estimated to Be $Q _ { d }$

Multiple Choice

If demand is estimated to be $Q _ { d }$ = 240 -6P,the marginal revenue function is

A) MR = 40 - 0.33Q.
B) MR = 240 - 2Q.
C) MR = 40 - 2P.
D) MR = 240 -12P.
E) MR = 240 -6P.