Ralph was considering hiring George to work in his grocery store as a shelf stocker. To ensure that George is a citizen or permitted to work in the United States, Ralph should ask George to complete the following document:

An I-9 Employment Eligibility Verification form

Explanation:

Ralph should ask George to fill the I-9 Employment Eligibility Verification form.  This form is used to verify the identity of a job seeker and if the are eligible for employment in the United states. It is mandatory that all US employer must duly complete these forms for every individual they employee. In the form, it is stated whether the individual is an American citizen or non-citizen and if he or she is permitted to work or not in the United States.

rain should be the answer.