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, the mixed economy, and so on. Option (a): The economic system is the organization that determines the basic economic problems of the economy. The question of what to produce includes the economy's decision to produce the goods and services that are using the resources of the economy. The command economy is the economy, which is ruled by a commanding authority, basically a central government that is very strong. Therefore, the basic economic questions are determined by the central authority under the command economy. Thus, option 'a' is correct. Option (b): The individual buyers and sellers form the market of the economy. When the market has the power to determine the basic economic questions such as what and how to produce and for whom to produce, the economic system is known as capital economy...