Improvements in transportation led to A. Lower shipping costs for goods
B. Fewer settlers moving westward
C. increased communication times
D. Higher prices for empty lands

A- lower shipping costs for goods

Explanation:

Being that the goods got where they had to be quicker, it was less money to move them

answer; /// i do believe that the correct answer is (a); a farming tribe that settled primarily along the mississippi and arkansas rivers;