We can learn about the living conditions of a vanished culture by examining its language. Thus, it is likely that the people who spoke Proto-Indo-European, the language from which all IndoEuropean languages descended, lived in a cold climate, isolated from ocean or sea, because ProtoIndo-European lacks a word for "sea, "yet contains words for "winter, ""snow, " and "wolf. " Which one of the following, if true, most seriously weakens the argument? ['Some languages lack words for prominent elements of the environments of their speakers.', 'A word meaning "fish"was used by the people who spoke Proto-Indo-European.', 'The people who spoke Proto-Indo-European were nomadic.', 'There are no known languages today that lack a word for "sea. "']