A model is made of a car. the car is 9 feet long and the model is 6 inches long

A model is made of a car. the car is 9 feet long and the model is 6 inches long. what is the ratio of the length of the ar to the length of the model?

a. 18 : 1
b. 1 : 18
c. 9 : 6
d. 6 : 9