Answer
Originally, when there were three candidates, Candidate A was selected as the winner using the plurality method. After a losing candidate, Candidate B, drops out, Candidate A is not selected as the winner using the plurality method. Therefore, the irrelevant alternatives criterion is not satisfied.
Work Step by Step
When there were three candidates, Candidate A was selected as the winner using the plurality method, because Candidate A had the highest number of first-place votes in the original preference table.
We can see the preference table below after Candidate B drops out. Note that every other candidate below Candidate B on a ballot moves up one spot on that ballot after Candidate B drops out.
With the plurality method, the candidate with the highest number of first-place votes is selected as the winner. We can find the number of first-place votes for each candidate.
Candidate A: 400
Candidate C: 250 + 200 = 450
Since Candidate C has the highest number of first-place votes, Candidate C is selected as the winner using the plurality method.
Originally, when there were three candidates, Candidate A was selected as the winner using the plurality method. After a losing candidate, Candidate B, drops out, Candidate A is not selected as the winner using the plurality method. Therefore, the irrelevant alternatives criterion is not satisfied.