Math
posted by John .
The cars in a car service use a total of gallons of gasoline per week. If each of the cars uses the same amount of gasoline, then, at this rate, which of the following represents the number of gallons used by 5 of the cars in 2 weeks?
A. 10CG
B. 2G/5C
C. 5G/2C
D. G/10C
E. 10G/C
why is E correct, i do not understand the answer given by College Board for this SAT question of the day. Thank you in advance for the help!

1= 1 week for 1 car
also, the rest of the answers have bad form (magnitude then units usually)