Final answer:
The distinguishing feature of a command system is the government ownership of resources, which is in contrast to a market economy where resources are privately owned.
Step-by-step explanation:
A distinguishing feature of a command system, such as a command economy, is the government ownership of resources. In a command or planned economy, the government has direct control over the economy, including the means of production and distribution of goods. Private ownership of resources and capital are characteristics of a market economy, which operates under different principles where individuals and firms own resources and make production decisions. A circular flow of goods, resources, and money is a feature seen in both command and market economies, as it represents the economic transactions in any economic system.
Therefore, the distinguishing feature of a command system from the given options is B. government ownership of resources.