Answer:
1. An odd number of the factors were negative
Explanation:
If we have 4 numbers, for example 2 x 2 x 2 x 2 and an odd number of them were negative so we could have two outcomes: -2 x 2 x 2 x 2 and -2 x -2 x -2 x 2 each in the end would get -16. Now -16 multiplied by -2 gets 32 which is positive.