American trade policies during the period of isolationism contribute to the deep economic woes of the great depression. select the best answer from the choices provided t f

The telegraph, the transatlantic telegraph cable, and the telephone were important to businesses after 1850 because of a. they created a system for developing new inventions. b. they filled a need that other inventions of the day could not. c. they attracted investors and created the stock market. d. they made picture-taking a popular american pastime.