To analyze the given multiplication problem where the product is \( \sqrt{225} \):
First, we calculate \( \sqrt{225} \): \[ \sqrt{225} = 15 \]
Since 15 is a rational number, we can consider the implications for the factors of the multiplication problem.
- If the product is rational, both factors could be rational, or it’s possible for one factor to be rational and the other irrational, but we cannot conclude that both must be irrational.
From the information that the product is a rational number (15), we can assert that:
- They are both rational because the product is rational.
Therefore, the correct response is:
They are both rational because the product is rational.