When might a voter need to use a provisional ballot?

A provisional ballot is typically used in situations where a voter's eligibility or registration cannot be immediately confirmed at the polling place. This method ensures that the vote is counted once the voter's eligibility is verified.

When a voter has moved and failed to file an address change, their registration may not reflect their new address, which can result in them being ineligible to vote at that location. By using a provisional ballot, they can still participate in the election while providing the necessary information later to confirm their eligibility.

In the case of voting in their first election, while there can be confusion about the voting process, it does not inherently necessitate a provisional ballot unless there’s an issue with their registration. Similarly, wishing to change political party affiliation or not knowing one's polling location does not directly impact one's eligibility to vote but could require assistance or alternative steps rather than the use of a provisional ballot. Thus, the scenario described in the correct choice directly relates to voter eligibility issues, making it the appropriate situation for utilizing a provisional ballot.