On the first day of class, Professor Wallace tells her students that pop quizzes will be given at unpredictable times throughout the semester. Clearly, studying for Professor Wallace's surprise quizzes will be reinforced on a schedule.

Which statement best represents an economic weakness of the national government under the articles of confederation? a. the national government was unable to collect taxes. b. national and state taxes combined were too high for most services to pay. c. congress set different tax rates for each state, leading to conflict. d. state refused to collect taxes on behalf of the national government