单项选择题
public class Pet{
private String name;
public Pet(){
System.out.print(1); }
public Pet(String name){
System.out.print(2); } }
public class Dog extends Pet{
public Dog(String name){
System.out.print(3); } }
执行new Dog(“棕熊”);后程序输出是哪项?()
A. 23
B. 13
C. 123
D. 321