What quote from the book Lord of the Flies best represents the theme of society in the conch?

"'And another thing. We can't have everybody talking at once. We'll have to have 'Hands up' like at school.'
He held the conch before his face and glanced round the mouth.
'Then I'll give him the conch.'
'Conch?'
'That's what this thing is called. I'll give the conch to the next person to speak. He can hold it when he's speaking.'"

It's early days on the island, and the boys are still trying to establish some measure of order and stability. Ralph knows that some kind of rules-based system is essential to achieve this goal. The boys could copy what they do at school when they wish to speak in class—raise their hands. But they're not at school now; there are no adults or any other authority figures around. They're still children, but they need to act like responsible adults. This is where the conch comes in.
Ralph establishes the conch as a symbol of quasi-legal authority on the island. From now on, it will represent an ideal of social organization that will be seriously challenged by Jack and his gang of savages before being destroyed altogether.