What is the difference between a market economy and a command economy?

A. A market economy is determined by central authority and a command economy is determined by consumers.

B. A market economy is determined by consumers while a command economy is determined by both consumers and central authority.

C. A market economy is determined by both central authority and consumers while a command economy is determined by only consumers.

D. A market economy is determined by consumers and a command economy is determined by central authority.​