The correct answer is <span>The need for natural resources and new markets
Imperialism is the idea that the United States actually should expand beyond its borders, which it did when it went westwards or when it took the Philippines. Being isolated is also against the idea of imperialism, while immigration is not as related to the idea. The only thing here is the need for resources and new markets which is a part of imperialism.</span>
Explanation: C gives us a strong reason why reclamation has gotten cheaper. The nature of the mines has changed, making it less difficult to reclaim them.
B looks good EXCEPT look very carefully at the wording of the argument.
Economic growth can reduce poverty by doing all of the above. Growth benefits all aspects of society--public and private--and often occurs in areas where there is lots of competition.
