Answer: The right answer is the C) ¡Venga a nuestra casa!
Explanation: Just to elaborate a little on the answer, it can be added that in this exercise they are asking you to use an imperative form of the verb in order to address somebody politely (since she is your elderly aunt). "Venga" corresponds to the second person singular voice "usted," which is what you would use in order to invite someone politely. "Ven" is used with the second person singular, but it corresponds to the form "tú," which is less formal. "Viene" agrees with the third person singular, and "venimos" agrees with the first person plural, and they are not conjugated in the imperative form.