Which situation can be represented by a true proportion?
A. A car use 3 gallons of gas to drive 72 miles on a highway and used 4 gallons of gas to drive 72 miles in town.
B. A signal light flashed yellow 7 times in 28 seconds and flash red 5 times in 35 seconds.
C. An alarm on a clock beeped 7 times in 6 seconds and beeped 14 times in 12 seconds.
D. A store charged $20 for 2 shirts and charged $25 for 3 shirts.