27. What is the effect of the implements keyword in the following declaration? public class ClassA implements interfaceB A. It requires ClassA to provide an implementation for all methods declared in interface. B. It makes ClassA a subtype of interface. C. It makes it possible to store references to objects of ClassA in variables of type interface. D. All of the above (ANSWER) E. None of the above 28. What is the effect of declaring a field private in Java, as opposed to public? A. It is not possible to modify the value of a private field. B. Private fields cannot be accessed by code in classes other than the class declaring the fields. (ANSWER) C. Private fields cannot be accessed by static methods. D. Private fields cannot be accessed by instance methods. E. None of the above