1. In class, we saw how we could use a for loop to calculate the sum of some numbers.
Each of the following loops is an attempt to sum up the numbers from 1 to n (you
can assume n is initialized).  For each case, explain why this doesn't actually
sum the numbers 1 through n.

a.

sum = 0

for i in range(n):
    sum = sum + i

b.

sum = 0

for i in range(n):
    temp = sum + (i+1)

sum = temp

c.

sum = 0

for i in range(n):
	sum = (i+1)

d.

sum = 0

for i in range(n):
	temp = (i+1)
	sum = temp