What event caused the oregon trail to end in 1869? please help this is due in 3 mins

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.