During the 1920's, the supply of automobiles in the united states increased because of the introduction of the assembly line and mass production. which is the best description of the effect that high supply had on the price of automobiles during this time period? a) the high supply of automobiles led to fewer sales. b) the price of new autos increased because of high supply. c) the price of new autos decreased because of high supply. d) the price of new autos was not affected by the introduction of the assembly line.