Previously, most vehicle manufacturers ignored fuel efficiency in favor of speed and performance. Fuel efficiency was difficult to engineer and manufacturers paid little attention to excessive fuel consumption in developing their designs. This year the most sold vehicle in the United States has been the most fuel efficient one—a certain sign that manufacturers are becoming more concerned with limiting wasteful fuel usage than optimizing a vehicle’s speed.
Which of the following, if true, most seriously weakens the argument above?
【选项】
The price of aluminum reached record highs this year and all vehicles are more expensive to manufacture as a result.
选项是否正确？