4. A class that will respond to button press events must use which phrase in its header? Point 20 a. import java.event b. extends Action c. extends JFrame d. implements ActionListener Ans: AJFrame contains a JButton named buttonl that should execute an actionPerformed0 method when clicked. Which statement is needed in the JFrame class? a. addActionListener(this); b. addActionListener(buttonl); c. button1.addActionListener(this); 5. d. this.addActionListener(buttonl); Ans