【单选题】If the old maxim that the customer is always right still has meaning, then the airlines that ply the world's busiest air route between London and Paris have a fight on their hands. The Eurostar train ...
A.
they are more powerful than other European airlines
B.
their total loss won't go beyond a drop of 5~ passengers
C.
their traffic levels will return in 2-3 years
D.
traveling by rail can never catch up with traveling by air