Suppose that forest owners consider both the current and all future forest stands when choosing an optimal rotation length. You are responsible for instituting a policy that increases the amount of land that is devoted to forestry. Which of the following policies should you choose?

a. None of these policies will increase the amount of land devoted to forestry.

b. A policy that increases the discount rate of all landowners.

c. A site-use tax that increases the fixed cost of forestry

d. A site-use subsidy that decreases the fixed cost of forestry.