Economist: Money, no matter what its form and in almost every culture in which it has been used, derives its value from its scarcity, whether real or perceived. Anthropologist: But cowrie shells formed the major currency in the Solomon Island economy of the Kwara' ae, and unlimited numbers of these shells washed up daily on the beaches to which the Kwara' ae had access. Which one of the following, if true about the Kwara'ae, best serves to resolve the apparently conflicting positions cited above? ['They accepted as money only cowrie shells that were polished and carved by a neighboring people, and such shell preparation required both time and skilled labor.', 'After Western traders brought money in the form of precious-metal coins to the Solomon Islands, cowrie-shell money continued to be used as one of the major media of exchange for both goods and services.', 'They considered porpoise teeth valuable, and these were generally threaded on strings to be worn as jewelry.', 'During festivals they exchanged strings of cowrie-shell money with each other as part of a traditional ritual that honored their elders.']