What is the output of the following code?

```
#include
using namespace std;

void f(double &p)
{
p += 2;
}

int main()
{
double x = 1;
double y = 1;

f(x);
f(y);

cout << "x is " << x;
cout << " y is " << y << endl;

return 0;
}
```

a. x is 2 y is 1
b. x is 3 y is 3
c. x is 2 y is 2
d. x is 1 y is 1
e. x is 1 y is 2

b. x is 3 y is 3