The Graph of a Function F Is Given $\mathrm { f } ^ { - 1 } ( \mathrm { x } )$

Multiple Choice

The graph of a function f is given. Use the graph to find the indicated value.
-Let f(x) compute the cost of a rental car after x days of use at $42 per day. What does $\mathrm { f } ^ { - 1 } ( \mathrm { x } )$ compute?

A) The number of days rented for 42 dollars
B) The cost of rental for 42 days
C) The cost of rental for x days
D) The number of days rented for x dollars