Production was often inefficient under communist rule because people

The correct response is "people had little incentive to work efficiently."

Explanation:

Scholars who critique the communist model of society often stress how it lacks the competitiveness that is inherent to a free market system. Workers in a communist system join unions that are ultimately controlled by the state where wages are set by the government and there is little differential between different skills and talents. Thus the worker in a communist system has little incentive to perform better than their peers or to aspire to a higher position in terms of their employment following this logic.