. . . since they have no use for money among themselves, but keep it as a provision against events which seldom happen, and between which there are generally long intervening intervals, they value it no farther than it deserves—that is, in proportion to its use. So that it is plain they must prefer iron either to gold or silver, for men can no more live without iron than without fire or water; but Nature has marked out no use for the other metals so essential as not easily to be dispensed with. –Utopia,
Thomas More

What is the central idea of this passage?

The Utopians use money only within Utopia.
The Utopians value money less than other, more useful things.
The Utopians prefer gold and silver to other metals, such as iron.