Given the following program, which line(s) cause(s) output to be displayed on the screen?

```
1 // This program displays my gross wages.
2 // I worked 40 hours and I make $20.00 per hour.
3 #include
4 using namespace std;
5
6 int main()
7 {
8 int hours;
9 double payRate, grossPay;
10
11 hours = 40;
12 payRate = 20.0;
13 grossPay = hours * payRate;
14 cout << "My gross pay is $" << grossPay << endl;
15 return 0;
16 }
```

a. lines 13 and 14
b. lines 8 and 9
c. line 14
d. lines 14 and 15
e. line 15

c. line 14