Pls Hurry 
Best answer gets brainliest 
On a roadtrip, the distance driven can be represented by
the following equation
y = 15x 
where x is the number of gallons of gas.
What does the 15 represent?
A) 15 gallons of gas were used 
B) the gas cost $15
C) the road trip was 15 miles long 
D) the car traveled 15 miles per gallon