Answer:
(E) many roads were built for profit by private companies.
Explanation:
Shortly after obtaining independence (in the early nineteenth century precisely), the United States had a need for roads in order to improve its economy.
The federal government was not very large or powerful, and it did not have a lot of money to spend (neither were state governments), thus, many private companies began to build roads with private funds, and in order to get a return on the investment, they added turnpikes to the roads in order to charge a toll.