A) Which of the following statements are true?

1. A Java class can implement only one Java interface 2. A concrete class can extend only one parent class, but an abstract class can extend any number of parent classes 3. A Java class can only extend one parent class 4. A Java class can implement any number of Java interfaces

B) Which of the following can appear in a concrete class?

1. constants (finals) 2. abstract methods 3. variables 4. code to implement methods

C) Which of the following can appear in an abstract class?

1. method signatures for public methods 2. method signatures for private methods 3. code to implement methods 4. constants (finals) 5. variables

D) Which of the following can appear in a Java interface?

1. method signatures for private methods 2. method signatures for public methods 3. variables 4. constants (finals) 5. code to implement methods