the correct answer from the given options is 3+.
Aluminum is a metal from group 13 in the periodic table and it always loses three electrons and make an ion which carry a charge 3+.
when an atom loses an electrons, it will carry positive charge and when an atom gains an electrons it will carry positive charge. In the case of aluminum it loses electron so it will carry positive charge and loses 3 electrons so the charge on the ion is 3+.