单选题：Consider the following definitions of function `fun` , which on

Consider the following definitions of function `fun` , which one is **correct** ?
@[D](1)

A. ```
double fun(int x,int y)
{z=x+y;return z;}```
B. ```
fun(int x,y)
{int z;
return z;}```
C. ```
fun(x,y)
{int x,y; double z;
z=x+y;return z;}```
D. ```
double fun(int x,int y)
{double z;
z=x+y;return z;}```




A.```
double fun(int x,int y)
{z=x+y;return z;}```
B.```
fun(int x,y)
{int z;
return z;}```
C.```
fun(x,y)
{int x,y; double z;
z=x+y;return z;}```
D.```
double fun(int x,int y)
{double z;
z=x+y;return z;}```


答案：D