Which of these was the biggest influence on the wealth of the chinese city of Chang'an? A. the end of the Mongol threat
B. the popularity of the Silk Roads
C. the completion of the Great Wall
D. the increased power of China's navy

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.