The children were making each other laugh, they did this via what?
Options:
- play ball
- reading a book
- jump rope
- tickle
- see exhibits
Let's think now! Step-by-step reasoning:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Tickling leads to laughing. Children like to tickle others. Tickling involves touching another person.
So, the final answer is tickle.