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

Improvements in transportation led to : A. Lower shipping costs for goods

Improvement in transportation usually followed by increased in efficiency, whether it's a larger space to deliver goods or fewer fuel needed to reach the destination. Both will lead to lower shipping cost

hope this helps

Idon’t know who knows but i know who does not know me