a. tariffs: to protect domestic industry.
b. anti-fraud laws: to guarantee free choice.
c. environmental protection laws: to safeguard natural resources.
Tariffs are taxes that are placed on imports between states. They are often used as a way to protect domestic industry.
A fraud is a deliberate deception to secure some legal gain, or to deprive a victim of a legal right. Anti-fraud laws are passed to prevent and punish this type of behaviour.
Environmental protection laws are those that are created in order to protect natural ecosystems from human destruction.