Given:
11. abstract class Vehicle { public int speed() { return 0; }}
12. class Car extends Vehicle { public int speed() { return 60; }}
13. class RaceCar extends Car { public int speed() { return 150; }}
…
21. RaceCar racer = new RaceCar();
22. Car car = new RaceCar();
23. Vehicle vehicle = new RaceCar();
24. System.out.println(racer.speed() + “, ” + car.speed()
25. + “, ” + vehicle.speed());
What is the result?
A.
150, 150, 150
B.
150, 60, 0
C.
An exception is thrown at runtime.
D.
0, 0, 0
E.
Compilation fails.
Explanation: