单选题

public class TestPass { String str = new String("hello"); char[] ch = {'a','b','c'}; public static void main(String[] args) { TestPass ex = new TestPass(); ex.change(ex.str,ex.ch); System.out.print(ex.str + " and "); System.out.print(ex.ch); } private void change(String str,char[] ch) { str = "test ok"; ch[1] = 'g'; } } 程序运行结果？

Question

A. hello and abc

B. hello and ag

C. hello and ac

D. hello and agc