Subject: mathqa
Question: a certain car uses one gallon of gasoline every 32 miles when it travels on highway , and one gallon of gasoline every 20 miles when it travels in the city . when a car travels 4 miles on highway and 4 additional miles in the city , it uses what percent more gasoline than if it travels 8 miles on the highway ?
Option: 
A: 30 %
B: 25 %
C: 22.5 %
D: 20 %
Answer: A