C. Check your answers and present the solution is the correct answer!
Banks loaned money to rich tycoons who were expanding the railroads
Hillary Clinton, Donald Trump, Gary Johnson, Jill Stein, Ted Cruz, Bernie Sanders, Marco Rubio, Rand Paul, Ben Carson, John Kasich, Mike Huckabee, Carly Fiorina, Chris Christie, Martin O'Malley, Jeb Bush, Rick Santorum, Jim Gilmore, George Pataki, Lindsey Graham, Lincoln Chafee, Bobby Jindal.
Answer:
the answer is A. all of these options
It was faster and cost less. It made the population grow and it caused modernization. But it also had environmental hazards and it was sometimes dangerous.