Principle: If the burden of a proposed policy change would fall disproportionately on people with low incomes, that policy change should not be made. Application: The city of Centerburgh plans to reintroduce rock salt as a road de-icing agent, after having stopped its use several years ago on the grounds that it accelerated the corrosion of automobiles. Although the city claims that cars are now better protected from salt' s corrosive properties than they were even as recently as five years ago, the city' s plan should be halted. Which one of the following, if true of Centerburgh, most justifies the above application of the principle? ['Road maintenance is primarily funded by local sales taxes, which disproportionately burden people with low incomes.', 'People with low incomes are more likely to purchase older vehicles than are people with higher incomes.', 'Individuals with low incomes are more likely to use public transportation and are less likely to drive cars than are individuals with higher incomes.', 'Cars now cost twice what they did when rock salt was last used as a road de-icing agent.']