Bevex, an artificial sweetener used only in soft drinks, is carcinogenic for mice, but only when it is consumed in very large quantities. To ingest an amount of Bevex equivalent to the amount fed to the mice in the relevant studies, a person would have, to drink 25 cans of Bevex-sweetened soft drinks per day. For that reason, Bevex is in fact safe for people. In order for the conclusion that Bevex is safe for people to he properly drawn, which one of the following must be true? ['Cancer from carcinogenic substances develops more slowly in mice than it does in people.', 'People drink fewer than 25 cans of Bevex- sweetened soda per day.', 'If all food additives that are currently used in foods were tested, some would be found to be carcinogenic for mice.', 'People can obtain important health benefits by controlling their weight through the use of artificially sweetened soft drinks.']