The tops of vents from gasoline tanks should terminate（）.

A.actuator
B.annulus
C.accumulator
D.annular preventer

A.controls the amount of gasoline to the engine
B.shuts off the gasoline supply at the tank
C.is used if the gasoline tank leaks
D.All of the above

A.pressure
B.toxicity
C.temperature
D.flammability