Three girls and two boys were dancing. They danced in pairs so that each girl danced with each boy for exactly one minute. At any time, there was only one pair on the dance floor. For how many minutes did they dance? (2021 Math Kangaroo Problem, Level 1-2, Question \#21) 
选项为:A:$$5$$  B:$$6$$  C:$$8$$  D:$$9$$  E:$$10$$  请回答其中一个选项.