They find pearls on their coasts, and diamonds and carbuncles on their rocks; they do not look after them, but, if they find them by chance, they polish them, and with them they adorn their children, who are delighted with them, and glory in them during their childhood; but when they grow to years, and see that none but children use such baubles, they of their own accord, without being bid by their parents, lay them aside, and would be as much ashamed to use them afterwards as children among us, when they come to years, are of their puppets and other toys. –Utopia,
Thomas More

What is the central idea of this passage?

The Utopians use pearls, diamonds, and carbuncles for trade.
The Utopians use valuables to gain an advantage over other societies
The Utopians give valuables to children, who treat them as toys.
The Utopians allow only children to search for pearls, diamonds, and carbuncles.