The product of a multiplication problem is 225−−−√

The square root of 225 is \( \sqrt{225} = 15 \), which is a rational number. Therefore, the product is rational.

Based on the properties of multiplication:

- If both factors were rational, the product would also be rational.
- If one factor is irrational, then the product can still be rational if the other factor is a specific rational number that cancels out the irrational part (for example, multiplying by its conjugate).

However, since \( \sqrt{225} \) is rational (equal to 15), this indicates that both factors could likely be rational.

Given this, the correct response is:

**They are both rational because the product is rational.**