This historian would be using the skill of "comparative analysis," since he or she is comparing a wide variety of sources to draw a conclusion between them as a group.
The answer is B. the United States.
The line is "I pledge allegiance to the flag of the Unites States of America."
The technology rail roads had made transportation a lot more easier as it was able to provide easy access of transportation among the people, the free enterprise system is where the government laid rules of which are only few and are restricted for the contribution of those who are participating and for the sake of balance among the market in which had made a rise in the national markets because of this system and the population were a part of it as every development and achievement were because of the people involved.
Longevity in life and a brighter future for technology
