阅读下列代码片段 class InterestTest______ActionListener{ public voidactionPerformed(ActionEventevent){ double interest=balance*rate/100; balance+=interest; NumberFormat format=Number Format.getCurrencylnstance(): System.out.print]b('balance='+formatter.format(balance)}; } Privatedoublerate; } 在下划线处,的正确选项是( )。