Answer:
The answer is D. government actions that reduce competition from international firms
Step-by-step explanation:
A tariff is a form of tax imposed by a government on goods and services imported from other countries. A tariff may be levied either to raise revenue or to protect domestic industries. On the other hand is quotas(import quotas) is a form of trade restriction that sets a physical limit on the quantity of a good that can be imported into a country in a given period of time.
Therefore, changes in tariffs and quotas are government actions that reduce competition from international firms.