PLEASE HELP ASAP ILL RATE YOU BRAINLEAST I ONLY HAVE 15 MINUTES!!
People stopped using the Santa Fe Trail for shipping when_______
a. the automobile was invented.
b. stagecoach became available for public use.
c. airplanes became the primary mode used to transport goods.
d. the railroad ended shipments by caravan.
Please select the best answer from the choices provided ​