A bowling alley charges its customers an hourly rate to bowl plus shoe rental. The hourly rates are per lane.

A linear model of this situation contains the values (2, 41) and (3, 59.25), where x represents the number of hours bowled on one lane, and y represents the total cost for bowling.

What is the rate of change in this linear model?
A.
$4.50 per hour
B.
$18.25 per hour
C.
$36.50 per hour
D.
$9.12 per hour