给定以下代码，程序的运行结果是 （）public class Example {String str=new String("good");char [] ch={'a','b','c'};public static void main(String[] args) {Example ex=new Example();ex.change(ex.str, ex.ch);System.out.print(ex.str+"and");System.out.print(ex.ch);}public void change(String str,char ch[]){str="test ok";ch[0]='g';}} A: goodandabc B: goodandgbc C: test okandabc D: test okandgbc