Why was the National Road unsatisfactory to farmers in a commercial se

Why was the National Road unsatisfactory to farmers in a commercial sense?

A) Shipments of bulky goods like grain were too slow and expensive by road.
B) The National Road did not connect the East to the West.
C) The road dramatically reduced costs and travel times, but was very dangerous.
D) The road did little to facilitate the movement of people.

ANSWER
Answer: A