Which of the Following Is True of the Steamboat Era

Which of the following is true of the Steamboat Era?

A) During this era, many southerners considered the funding of other internal improvements necessary.
B) Steamboats led to a reduction in cargo rates across the country.
C) Steamboats proved to be an ineffective means of transport.
D) During this era, steamboats became the cornerstone of the American transportation revolution of the 1840s and 1850s.
E) Steamboats became the most transformative new form of transportation in the country.