Explanation An economic system is an organization that determines the basic answers to the economic questions such as what to produce, how to produce, for whom to produce, and so on. Thus, the economic system is the organization such as the capital economy, command economy, mixed economy, and so on. Option (d): The economic system determines the answers for the central economic problems or questions such as what to produce, how to produce, and for whom to produce. When the authority to answer these basic economic questions is with the government, it means that the government will own the economic resources and operate the economy through a centralized decision making process. This kind of economic system is known as socialism. Therefore, option 'd' is correct. Option (a): The economic system in which the tradition is used to answer the economic question is known as the traditional economies...