What error in this program needs to be fixed?

def sum(num1, num2)
return num1 + num2
print(sum(4, 5))
(1 point)
The first line needs a colon at the end.
The second line needs a colon at the end.
The final line needs a colon at the end.
The final line needs a plus sign instead of a comma.

The final line needs a colon at the end.