A. This is precisely when one must wash one’s hands. Before washing hands ritually, a person must check that their hands are physically clean. If the hands are dirty they must be washed and dried in the normal way, and only then does the ritual washing apply.
Originally it was a priestly duty to wash the hands before eating but the ancient Pharisees extended it to apply to every Jew. So before eating bread, everyone should wash their hands (pouring the water on each hand from a vessel) and say the blessing.