What happens next in this paragraph?

The gymnast swing from the border of the bars, the jumps to stand on the hands and make tuns. then
Available choices: I. , the gymnast flips in the air and lands stand on the mat.; II. , the gymnast started flipping and twirling on the bars.; III. the gymnast jump, somersaults and cartwheel on the feet.; IV. , the gymnast do the tappings using two hand, then he join the judges and count.;
I.