Answer:
monopolistic competition
Step-by-step explanation:
In a free-market system, the citizens have the most control over the resources. Meaning that there will be very little government intervention within the free-market system.
Communism, government planning, and socialist planning require the government to play a bigger role in the ownership an distribution of resources. This contradict the basic nature of the free-market system.
Monopolistic competition on the other hand, could happen in a free-market system. Especially if there is a single organization who managed to win over the market in a dominant fashion. Making the other competitors have no choice but to bail out.