The central problems relating to how much and what to produce are solved through the coordination of economic activities brought by the price signals. This is a feature of :

Market economy

The correct answer is option (4) : Market economy

In a market economy, the central problems of what and how much to produce are typically addressed through the coordination of economic activities facilitated by price signals in the market. This is in contrast to centrally planned or socialist economic where the government plays a more direct role in making these decisions.