The Text Quotes a Study by Political Scientist Larry Bartels

The text quotes a study by political scientist Larry Bartels comparing the preferences of constituents who are wealthy, middle class, and poor with the voting of senators on government spending, abortion, civil rights, and the minimum wage. The study found that

A) senators were equally responsive to the wealthy, the middle class, and the poor.
B) senators were more responsive to the opinions of the middle class than to those of the wealthy or the poor.
C) senators were more responsive to the opinions of the wealthy than to those of the middle class, and weren't at all responsive to the poor.
D) senators were most responsive to the poor.
E) senators weren't responsive to the rich, the middle class, or the poor.