Answer:
Silver ion
Step-by-step explanation:
In an electrolytic cell, the positive ions known as the cations migrate to the negative electrode, the cathode where they accept electrons to become discharged as neutral atoms. Also, the negative ions known as the anions migrate to the positive electrode, the anode, where they give up their electrons to become discharged as neutral atoms.
From the question above, the only positive ion among the options given is the silver ion, Ag+, therefore, it is the correct option.