M: The traffic is becoming worse and worse. I think there'll be huge changes in the ways people use cars. New laws will be made about what kind of car you can own and when you can drive. W: Maybe there'll just be too many of them on the roads. The air will be so seriously polluted that nobody will be able to breathe. M: Exactly. People will have to rely on trains. W: Why do you say that? M: Well, we won't be able to use cars, and airports take up too much space. That leaves trains. W: Huh. So do you think there'll be more efficient train systems between cities? M: Sure. They'll enable people to travel between cities in a matter of hours. There may even be trains going under the oceans to connect the main continents. W: Under the oceans? Oh, no! I get nervous enough flying on a plane., Question: What will too many cars lead to according to the woman? (A) Air pollution. (B) Traffic jam. (C) Oil shortage.
(A) Air pollution.