Pat can either drive to work, which takes half an hour and uses $1.50 worth of gas, or take the bus, which takes an hour and costs $1.00. How should Pat get to work?
A.Pat should drive because it saves half an hour relative to taking the bus.
B.Pat should drive if saving half an hour is worth $0.50 or more.
C.Pat should take the bus if saving half an hour is worth $0.50 or more.
D.Pat should take the bus because it costs $0.50 less than driving.
正确答案：Pat should drive if saving half an hour is worth $0.50 or more.
