I would look at your textbook to see how they define an invitee. A customer in a restaurant is definitely not a licensee or a social guest., S/he might be an invitee, since the restaurant is open for business and welcomes the public, and if the restaurant has done any advertising or promotions, and the customer is responding to that, then s/he is there because s/he was invited. If that doesn't match the definition in your textbook, then the answer is "none of the above". I've been teaching marketing for 30 years, and these terms are not common to most marketing textbooks, so they have to be specific to yours.
