【正确答案】 D

【答案解析】Argument Evaluation
Situation Ten years ago a county had slightly more taxpayers than registered voters. Since then the number of taxpayers has doubled, while the number of registered voters has increased less.
Reasoning What can be deduced from the information about the changing numbers of taxpayers and registered voters?There were already slightly more taxpayers than registered voters ten years ago, but since then the number of taxpayers has increased more than proportionately to the number of registered voters. It follows that there must still be more taxpayers than registered voters, that the absolute number of taxpayers must have increased more than the absolute number of registered voters has, and that the ratio of taxpayers to registered voters must have increased.
A Since there were already more taxpayers than registered voters ten years ago, and since the number of taxpayers has increased more than the number of registered voters, there must still be more taxpayers than registered voters.
B Although there are more taxpayers than registered voters overall, there could still be many individual registered voters who are not taxpayers.
C Since the number of taxpayers has doubled while the number of registered voters has less than doubled, the proportion of registered voters to taxpayers must have decreased, not increased as this option claims
D Correct. Since the number of taxpayers has doubled while the number of registered voters has less than doubled, the proportion of registered voters to taxpayers must have decreased.
E Since the number of taxpayers has doubled while the number of registered voters has less than doubled, the proportion of registered voters to taxpayers must have decreased, not remained unchanged.
The correct answer is D.