Suppose the MSC of cleaning Puget Sound is modeled as MSC = 10 + 1.4A, where A is the percentage of phosphorus abated and MSC is measured in millions of dollars.

a. Find the incremental costs of a policy initiative that increases the phosphorus abatement level from 30 percent to 40 percent.

b. Graphically illustrate using the MSC function, labeling clearly where incremental costs are shown.