Jaheon, Koo: Why do people eat popcorn in movie theater?

I was very anxious about the reason. why don't most of people eat other food like cookies in theater? So I searched for reason in internet. Why do people eat popcorn and coke in movie theater? If you chew food and drink like popcorn and coke in movie theater, you focus your attention on movie. Also, popcorn isn't bad smell and make small sound when people eat that. popcorn is satly and Coca-Cola did ad better than other companies. That's why people drink coke.