Please choose the correct ending to complete the given sentence: Using the pommel horse: . a gymnast wearing a red and white uniform

Ending1: prepares to mount a pommel horse for his exercise. Ending2: runs on four legs to the side of the parallel bars. Ending3: runs down a set of uneven bars on a gym floor. Ending4: approaches the bars holding a pole and begins to prepare himself for his routine.

Answer format: ending1/ending2/ending3/ending4