S Price Price D D 0 Q Q. 0 Q. Q Quantity Quantity 63. Refer to the above diagrams for two separate product markets. Assume that society's optimal level of output in each market is Co and that government purposely shifts the market supply curve from S to S in diagram (a) and from S to S, in diagram (b). We can conclude that the government is correcting for: A. negative externalities in diagram (a) and positive externalities in diagram (b). B. positive externalities in diagram (a) and negative externalities in diagram (b). C. negative externalities in both diagrams. D. positive externalities in both diagrams