This Graph Shows the Marginal Costs and Marginal Benefits Associated

Multiple Choice

This graph shows the marginal costs and marginal benefits associated with roadside litter clean up.Assume that the marginal cost and marginal benefit curves slope in the usual directions.
Refer to the information given above.The socially optimal number of bags of litter removed from the roadside is:

A) 10.
B) 15.
C) 20.
D) 30.