(Figure: Benefits of Asparagus) Suppose That Eating Asparagus Reduces the Incidence

(Figure: Benefits of Asparagus) Suppose that eating asparagus reduces the incidence of contagious disease. The external marginal benefit of asparagus is $3. To achieve the socially optimal quantity of asparagus, the government should:

A) subsidize the production of asparagus by $6 per pound, increasing output to 6,000 pounds.
B) tax the production of asparagus by $6 per pound, decreasing output to 6,000 pounds.
C) subsidize the production of asparagus by $3 per pound, increasing output to 4,000 pounds.
D) tax the production of asparagus by $3 per pound, decreasing output to 4,000 pounds.