Over the last 25 years, the average price paid for a new car has steadily increased in relation to average individual income. This increase indicates that individuals who buy new cars today spend, on average, a larger amount relative to their incomes buying a car than their counterparts did 25 years ago. Which one of the following, if true, most weakens the argument? ['Allowing for inflation, average individual income has significantly declined over the last 25 years.', 'There has been a significant increase over the last 25 years in the proportion of individuals in households with more than one wage earner.', 'During the last 25 years, annual new-car sales and the population have both increased, but new-car sales have increased by a greater percentage.', 'Sales to individuals make up a smaller proportion of all new-car sales than they did 25 years ago.']