Refer to the Below Supply and Demand Graph

Multiple Choice

Refer to the below supply and demand graph.Point A represents the current equilibrium level of output of this product and point B represents the optimal level of output from society's perspective.If government decides to correct this externality with a subsidy to consumers, then the:

A) demand curve will shift from D₂ to D₁.
B) supply curve will shift from S₁ to S₂.
C) demand curve will shift from D₁ to D₂.
D) supply curve will shift from S₂ to S₁.