Answer:
The best answer to the question: Which of the following is a reason to make voter registration more difficult, would be: Decrease election fraud.
Explanation:
When talking about elections, of any kind, there is always the worry of whether or not there will be fraud. The higher the number of voters registered to vote, the higher the likelihood of fraud being committed. However, when a process of registration for voting is made more unreachable to everyone, or at least, more difficult, people tend to get the idea that cheating, and committing fraud, will not be as easy, and they will tend to avoid getting involved in such things. The difficulty in registration for voters will give the idea that the authorities are on the alert, are aware of the possibility of such a thing happening, and thus discourage the intention altogether. This is why the best answer is the second one.