Use the Following Figure to Answer the Question : Figure

Multiple Choice

Use the following figure to answer the question : Figure 20-1 : D₁ and S₁ are the private demand and supply curves,of a commodity produced by a competitive firm.S₂ reflects the social marginal cost of production,while S₀ represents the external marginal cost.
-Refer to Figure 20-1.When the efficient output is being produced,the price of the good must be:

A) $90.
B) $108.
C) $100.
D) $40.