An industry consists a firm which has sells its product for $30 and has a marginal cost of $18. Calculate the Lerner index for this firm? What it its mark up factor?

Select one:

A. Lerner Index = 0.6 and Mark up = 2.5

B. Lerner Index = 0.4 and Mark up = 1.67

C. none of the answers are correct

D. Lerner Index = 0.4 and Mark up = 1.67

E. Lerner Index = 1.67 and Mark up = 0.4