Answer:
The correct answer is: VISITE.
Step-by-step explanation:
In Spanish the imperative form is used when expressing commands and you can only use it for the second person singular and plural, and its courtesy persons (usted/ustedes). Each has its own way to conjugate.
In order to do it correctly for the courtesy second person singular (usted) you must do it as it is done in the third person singular for present subjunctive, which is keeping the root and adding an "-e" termination.
In this case, the verb "visitar" (to visit) is regular, therefore follows the said rule, so as the root is "visit" and the termination is "-e", then the correct answer is: VISITE.