Please choose the correct ending to complete the given sentence: Using the rowing machine: A man is riding a rowing machine in a gym. a finger

Ending1: appears in front of him and he turns to find out why. Ending2: briefly covers part of the camera lens. Ending3: moves the levers in front of the machine. Ending4: taps on the windshield of the machine.

Answer format: ending1/ending2/ending3/ending4