Which of the following represents key strengths of the market economy as a system of allocation?
a. Goods and services are allocated based on willingness and ability to pay, rather than based on need.
b. Producers have strong incentives to innovate because successful innovators are rewarded with higher profit.
c. Since price is freely set based on supply and demand, shortages and surpluses are minimized.
d. All of the answers above are correct.