Answer: (q2 - q1).
Step-by-step explanation:
A free market is an economic system whereby production of goods and services are being regulated by demand and supply forces. In this economic system, it should be noted that there's little or no intervention from the government.
If a free market were allowed in the transplanted kidney market, then the equilibrium price would be p2. The number of kidneys transplanted would increase by (Q2-Q1) compared to the number transplanted at a price ceiling of p= $0.