Julio paid $27 to rent a scooter for 4 hours. Elsie paid $42 for 7 hour. Assuming the relationship is linear, write an equation in function form to represent the cost C, in dollars, of renting the scooter for h hours.

a h(C)=5C+7
b C(h)=7h+5
c h(C)=7C+5
d C(h)=5h+7