What does the following code try to accomplish?

Function Dothis(Num As Long) Dim i As Long, answer As Long answer = 1 For i = 1 to Num answer = answer * i Next i Dothis = answer End Function

a) Calculate the sum of integers from 1 to Num

b) Calculate the present value of Num cash flows

c) Calculate the factorial of Num

d) Calculate the future value of Num