The following problem is from the MBA.com's preparation CD.

A box contains 100 balls, numbered from 1 to 100. If three balls are selected at random and with replacement from the box, what is the probability that the sum of the three numbers on the balls selected from the box will be odd?

A) 1/4

B) 3/8

C) 1/2

D) 5/8

E) 3/4

The correct answer was C. Can anyone explain this to me? Thanks!