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

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

A) P = 40- 0.1667Q.
B) P = 240 - Q.
C) $Q _ { d }$ = 40 - P.
D) $Q _ { d }$ = 240 - 12P.
E) $Q _ { d }$ = 240 -3P.