Given the function, and the main function calling it: Which, if any, of the following choices is the output of the following code? What does this function do?

```
#include
using namespace std;

void func ( int& x, int & y)
{
int t = x;
x = y;
y = t;
}
int main()
{
int u = 3; v = 4;
// ...
cout << u << " " << v << endl;
func ( u, v )
cout << u << " " << v << endl;
// ...
}
```

a) 3 4
3 3
b) 3 4
4 3
c) 3 4
3 4
d) 3 4
4 4
e) none of the above. If you choose this, you must specify the output

b) 3 4
4 3

The code swaps the values stored in the caller's arguments