1990 editorial: Local pay phone calls have cost a quarter apiece ever since the 1970s, when a soft drink from a vending machine cost about the same. The price of a soft drink has more than doubled since, so phone companies should be allowed to raise the price of pay phone calls too. Which one of the following, if true, most weakens the editorial's argument? ['A pay phone typically cost less than a soft- drink machine in the 1970s.', 'Between the 1970s and 1990 the cost of ingredients for soft drinks increased at a greater rate than the cost of telephone equipment.', 'Technological advances made telephone equipment more sophisticated between the 1970s and 1990.', 'Government regulation of phone call prices did not become more stringent between the 1970s and 1990.']