单选题：For the code below, which one can replace the line 7?( )

For the code below, which one can replace the line 7?( ) @[C](2)


```Java
public class Base {
int w,x,y,z;
public Base(int a, int b) {
x=a;y=b;
}
public Base(int a, int b, int c, int d) {
x=a;y=b; // line 7
w=d;z=c;
}
}
```

A. Base(a,b)
B. this(a,b,x,y)
C. this(a,b)
D. Base(x,y)




A.Base(a,b)
B.this(a,b,x,y)
C.this(a,b)
D.Base(x,y)


答案：C