Table 10-2 the Following Table Shows the Private Value, Private Cost, and Cost

Multiple Choice

Table 10-2
The following table shows the private value, private cost, and social value for a market with a positive externality.
-Refer to Table 10-2. How large would a subsidy need to be in this market to move the market from the equilibrium level of output to the socially-optimal level of output?

A) $3
B) $5
C) $7
D) $9