Plz help! Which of these would be the BEST action in attempting to ease the problem of acid rain

Which situation is the best example of regulation in an economic system? a retail business just opened a new store in a community close to its original location. a small clothing shop slashed it prices to attract customers from a larger department store nearby. a farmers’ market has offered a special deal to customers from a nearby yoga school. a state agency has been created to monitor the production and distribution of sports drinks.