HELP What’s happening in Georgia with senate run off, and why is this necessary? What is the significance of this event?

A runoff election is essentially a rematch that is held when none of the candidates meet the criteria for winning. Under Georgia law, candidates must receive a majority of the vote to win an election. If no candidate breaks 50 percent, the top two vote-getters then face off again in a runoff election to determine the winner.

answer; i believe that the correct answer is (chronological order);