阅读下列代码片段 class InterestTest——ActionListener{ public'void actionPerformed(ActionEvent event){ double interest=balance*rate/1 00 ; balance+=interest; NumberFormat format=NumberFormat.getCur- rencyInstance; System.OUt.print]b('balance='+formatter. format(balance)); } Private double rate; } 在下画线处,的正确选项是( )。