Let F(x) Compute the Cost of a Rental Car After $\mathrm { f } ^ { - 1 } ( \mathrm { x } )$

Multiple Choice

Let f(x) compute the cost of a rental car after x days of use at $24 per day. What does $\mathrm { f } ^ { - 1 } ( \mathrm { x } )$ compute?

A) The cost of rental for 24 days
B) The number of days rented for x dollars
C) The number of days rented for 24 dollars
D) The cost of rental for x days