Calculate ln(x!) exactly, Sterling's approximation (xlnx - x), and the percentage error in Sterling's approximation.

a) ln(x!) = ln(x) + ln(x-1) + ... + ln(2) + ln(1)

b) Sterling's approximation = xlnx - x

c) Percentage error = [(Sterling's approximation - ln(x!))/ln(x!)] 100

d) None of the above