Assume you have two integer variables, num1 and num2. Which of the following is the correct way to swap the values in these two variables?

a. ```
int temp = num1;
num2 = num1;
num1 = num2;
```

b. ```
int temp = num2;
num2 = num1;
num1 = temp;
```

c. ```
num1 = num2;
num2 = num1;
```

d. ```
int temp = num1;
num2 = temp;
temp = num2;
num1 = temp;
```

e. None of these

b. ```
int temp = num2;
num2 = num1;
num1 = temp;
```