Analyze the following program fragment:

```
int x;
double d = 1.5;
switch (d) {
case 1.0: x = 1;
case 1.5: x = 2;
case 2.0: x = 3;
}
```
a. The program has a compile error because the required break statement is missing in the switch statement.
b. The program has a compile error because the required default case is missing in the switch statement.
c. The switch control variable cannot be double.
d. No errors.

c. The switch control variable cannot be double.
The switch value cannot be a floating-point number.