C++ quiz. What is the correct way to call the following func

What is the correct way to call the following function?

int sum(int a, int b)
{
    return a + b;
}

int sum(int a = 7, int b = 8);
sum(int 7, int 8);
sum(7, 8);
sum() : 7, 8;
sum(int a = 7, int b = 8);

Explanation

sum(7, 8) is the correct way to call function in C++. To find out more about functions, go to Functions at cplusplus.com

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