Consider the following C program: double foo (double); /* Line 1 */ int main()…

Consider the following C program:

double foo (double); /* Line 1 */

int main()
{

    double da, db;

    // input da

    db = foo(da);

}

double foo(double a)
{
    return a;
}

Assume the program is compiled in ISO C17 mode with GCC 14 or later, or Clang 16 or later, using default diagnostic severity. If Line 1 is deleted, which result best describes the compilation?