Medical Research Is Often Presented as an Example of a Positive

Multiple Choice

Medical research is often presented as an example of a positive externality.Which of the following options available to policymakers would encourage producers of medical knowledge to provide a socially optimal level of production?
(i) imposing price ceilings on selected medical procedures
(ii) placing taxes on the sale of prescription drugs
(iii) providing subsidies to these firms

A) (i) , (ii) and (iii)
B) (i) and (ii) only
C) (iii) only
D) none of the above