WILL GIVE BRAINLIEST, JUST ANSWER THESE 3 MULTIPLE CHOICE QUESTIONS A, B, C, or D

N 1901, banker John Pierpont Morgan (1837-1913) purchased Carnegie Steel for some $480 million, making Andrew Carnegie one of the world's richest men. That same year, Morgan merged Carnegie Steel with a group of other steel businesses to form U.S. Steel, the world's first billion-dollar corporation. The answer for 1 is A

Between 1880 and 1900, cities in the United States grew at a dramatic rate. ... Industrial expansion and population growth radically changed the face of the nation's cities. Noise, traffic jams, slums, air pollution, and sanitation and health problems became commonplace. The answer for the second problem is C

& the last question can be done in your own words if you want

By linking the nation, railroads helped increase the size of markets, providing greater opportunities for many industries. Huge consumers themselves, the railroads also stimulated the economy by spending extraordinary amounts of money on steel, coal, and timber, among other needs.

( I hope this helped !! )