18) The following program generates an error. Why? void Print Sum (int mnuml, int mum2) { cout << numl + mum2; int main () ( int yi y = Print Sum ( 4, 5); return 0; a. The void function is missing a "retum;" statement. b. The values 4 and 5 cannot be passed directly to PrintSum() c. main() has a retum statement that returns the value 0 d. PrintSum() has void return type, so cannot be assigned to a variable

19) Which XXX calculates the area using the CalcSquare() function? The formula to calculate the area of a circle is pi'r. double CalcSquare ( double x) { return x*x; double CalCArea (double r) { const doulble PI VAL = 3.14159265; XXX; main () ( << CalcArea(5.0); int Cout return 0: