Answer:
C. The factors had the same sign.
Step-by-step explanation:
Factors that had the same sign will have a positive product.
Two positive numbers will have a positive product.
For example, 3 times 3 is 9.
Two negative numbers will also have a positive product, because multiplying negative numbers by other negative numbers will cancel out the negative.
For example, -3 times -3 is 9.
So, C is correct