4(15 pts.) a) You are given a class named Clock that has one int instance variable called hours. Write a constructor with no parameters for the class Clock. The constructor should set hours to 12. b) Write the definition of a class Telephoneb. The class has no constructors or other methods, one instance variable of type String called number, and two static variables. One is of type int called quantity, initialized to 250; the other is of type double called total, initialized to 15658.92 c) Write the definition of a class Telephonec. The class has no constructors and one static method getFullNumber O. The method accepts a String parameter and returns a String object, adding 718- to the beginning of the String parameter