1. Why is the ability to redefine a method important in object-oriented programming? Choose all options that apply. (a) Because it allows us to add extra work to a method. (b) Because it allows us to introduce abstract methods that are redefined as concrete methods. (e) Because it allows us to provide a more accurate or faster definition in a subclass. (d) Because it allows us to disable a method in a subclass. (e) Because it allows us to change the meaning of a method. 2. Which of the following statements about multiple inheritance are true? Choose all options that apply. (a) It offers more modeling choices. (b) It makes it more difficult to write compilers and (fast) runtime systems. (e) It simplifies inheritance hierarchies. (d) It solves the problem of repeated inheritance. 3. Which of the following statements are true? Choose all options that apply. (a) Most superclasses are abstract. (b) Inheritance is preferable to composition. (c) Most superclasses are concrete. (d) Composition is preferable to inheritance. 4. In UMI. diagrams, how are abstract classes distinguished from concrete classes? Choose only one option. (a) Concrete classes are shown as boxes with dashed outlines. (b) Labels on abstract classes are shown in italics. (c) Labels on concrete classes are shown in italics. (d) Abstract classes are shown as boxes with dashed outlines. 5. What is an 'abstract' class? Choose only one option. (a) An object. (b) A class with no methods. (e) A class with no concrete subclasses. (d) A class with at least one undefined message. (e) An interface. 6. Which of the following terms best describes the case where a Stack class is implemented using an internal instance of List? Choose only one option. (a) Association. (b) Specialization. (c) Genericity. (d) Composition. (e) Singularity. 7. With reference to Figure 3.14, what is the difference between the two diagrams? Choose only one option. (a) In Diagram 1, color is public but in Diagram 2 color is private. (b) Diagram 2 indicates that the car's color can be removed and replaced. (c) Diagram 1 shows an abstract class and Diagram 2 shows a concrete class. (d) None, they mean the same thing. Car color Car Color color: Color Diagram 1 Diagram 2