According to Duggan and Morton,the Reduction in Overall Drug Expenditures

According to Duggan and Morton,the reduction in overall drug expenditures

A) Is due to a decrease in prices by pharmaceutical companies
B) Is due to an increase in prices by pharmaceutical companies
C) Is due to the ability of private plans to drive the use of drugs toward less expensive therapeutic substitutes
D) Is due to the ability of Medicare Part D plans to drive the use of drugs toward less expensive therapeutic substitutes