阅读下列代码片段 class InterestTest________ActionListener{ public void actionPerformed (ActionEvent event) { double interest = balance * rate/100; balance += interest; number Format format =Number Format.getCurrencyInstance (); System.out.printlb{"balance = "+Formatter.format (balance)}; } private double rate; } 在下划线处，应填的正确选项是：
A.Implementation
B.Inneritance
C.implements
D.extends
E.C
F.3
正确答案是C