Please choose the correct ending to complete the given sentence: River tubing: People sails in a rocky river on inflatable individual boats. The boats pass with difficulty between the rocks. then

Ending1: , the boats pass in the lake on the basically straight river. Ending2: , a man wake boards on a waterfall. Ending3: , people enters in more troubled waters. Ending4: , a man is in a pack, going in a diving board.

Answer format: ending1/ending2/ending3/ending4