Which of the following best describes Australian elections?

Australian elections are best described as preferential voting system.

Preferential voting, also known as ranked choice voting, is a ballot design used in some elections in Australia. Under preferential voting, voters rank candidates in order of preference, not just for their favorite candidate but also for subsequent lower preferences. If no candidate receives over 50 percent of the total first preference votes, then the candidate (or candidates) with the lowest preferences are excluded from the race, as their ballots, or votes are transferred, according to preferences.