Why Were Steamboats Especially Important in Improving Transportation in the American

Why were steamboats especially important in improving transportation in the American interior?

A) Steamboats were faster than flatboats and barges and could travel upstream, which resulted in a transformation of commerce on the inland river system.
B) Steamboats were the safest means of moving goods long distances.
C) No roads or canals were built west of the Appalachians before the Civil War.
D) Until the development of the internal combustion engine, railroads were impractical for long-distance transportation.