Answer:
Option A, canals were built, primarily in the North, is the right answer.
Step-by-step explanation:
Improvements in transportation became visible in the early phase of the Nineteenth Century. All the developments made in the field of transportation such as roads, canals, steamboats and railroads positively affected the economy of the United States. Initially, rivers and roads and later on canals and railroads helped people, agricultural and manufactured goods to move from one place to another. Such canals were primarily built in the North which also contributed to the jealousies and rivalries that later caused the Civil War.