The correct answer is A.
A market economy is characterized by no goverment intervention (this rules out options B and C). Therefore, property cannot be public and needs to be private.
Economic decisions are reached by the free interactions (free competition) of the economic agents (households, firms and public sector) in the domestic and international markets. Prices and exchanged outcomes are determined by the equilibrium between the desires of producers and consumers, both domestic and foreign ones, as a market economy partcipates in globalization and market integration processes. (which rules out option D).