Answer:
C. freely operating economy in which all markets are perfectly competitive. 
Explanation:
When we have a lot of producers and many consumers in an economy, the best way to achieve an efficient allocation of resources is to have a freely operating economy in which all markets are perfectly competitive. 
- In such a free economy, demand for goods and services are not controlled. 
- The consumers behavior towards purchasing will determine if producers should allocate more resources to a production process or not. 
- It is better to make such market competitive without interfering into how resources are managed and dispensed.