Please choose the correct ending to complete the given sentence: Building sandcastles: A man and a boy make a sand castle in the beach. people

Ending1: walk and board along side water rivers. Ending2: approach to watch the castle and start to make small house next the sand castle. Ending3: are using child's sand castles in the sand. Ending4: are pouring water on the shore.

Answer format: ending1/ending2/ending3/ending4