Answer: B. A household demands goods and services from the market and supplies factor inputs
Explanation: The economy entails effective management of a system, or especially its resources. As a system of production and distribution and consumption, it requires several level of organization between firms and households. While firms are engaged in marketing of goods and services, the household are engaged in placing demands for these products and services which they consume. They are also involved in the supply of factor inputs such as capital to fund production, human resources in form of labour, management etc. This interplay of roles is the driving force behind successful economies.