阅读下列代码片段 class InterestTest______ActionListener …… public void actionPerformed(ActionEvent event) double interest=balance * rate 100; balance +=interest; NumberFormat format=NumberFormat.getCurrencyInstance(); System.out.print]b(’balance=’+formatter.format(balance); Private double rate; 在下画线处，应填的正确选项是( )。
A．Implementation
B．Inheritance
C．implements
D．extends