Using fossil energy more efficiently is in the interest of the nation and the global environment, but major improvements are unlikely unless proposed government standards are implemented to eliminate products or practices that are among the least efficient in their class. Objection: Decisions on energy use are best left to the operation of the market. Which one of the following, if true, most directly undermines the objection above? ['Often the purchaser of a product, such as a landlord buying an appliance, chooses on the basis of purchase price because the purchaser is not the person who will pay for energy used by the product.', 'When energy prices rise, consumers of energy tend to look for new ways to increase energy efficiency, such as by adding insulation to their houses.', 'Whenever a new mode of generating energy, such as a new fuel, is introduced, a number of support systems, such as a fuel-distribution system, must be created or adapted.', 'It would be unrealistic to expect society to make the changes necessary to achieve maximum energy efficiency all at once.']