Answer:
b.) Who could prove their grandfathers vote
Step-by-step explanation:
Grandfather clause was a rule used in the US southern states like Alabama, Georgia, Carolina and so on at the ending of the 19th century. This law allowed only people who could prove their grandfathers or ancestors voted before the civil war or as at a particular date. The law was made so as to prevent poor and uneducated black Americans and their descendants from voting