The correct answer is "false."
It is false that the Santa Fe Trail was established in 1821 and initiated trade between Santa Fe and Los Angeles. First, the Santa Fe Trail was established in 1822. Secondly, the Santa Fe Trail did not initiate trade between Santa Fe and Los Angeles. It connected Santa Fe, New Mexico with the city of Franklin, Missouri.
This region was explored in 1821 by a pioneer called William Becknell. By the time the railroad started operations in this region by the 1880s, Santa Fe became an important stop to load goods that were traded to Méxco.