What proof is useful after voting?

Correct answer: Indelible ink mark on the finger

The direct answer is A: the indelible ink mark on the finger. After a voter has been identified and votes, election staff apply a mark that is difficult to remove quickly. The reasoning is: the mark shows that the person has already voted, so staff can help prevent the same person from voting again in that election. Option A is correct because the ink is a direct visible sign connected with completed voting. Option B, a party flag, shows political affiliation or campaign identity and proves neither that the person voted nor that voting was lawful. Option C, a speech leaflet, is campaign material and has no official evidentiary role after voting. Option D, a nomination form, is submitted by a candidate during the nomination stage, not by an ordinary voter after voting. The mark is a procedural safeguard, not a receipt showing which candidate was chosen; the secrecy of the vote must remain protected. Memory cue: ink indicates participation, never the voter’s choice.