I believe the answer is: C a creation of a more national unified American trading economy
The core strategy behind the American system is to increase the tariff that imposed to foreign products when they enter united states. By doing this, Clay hoped to create a unified American trading by making it easier for local Small businesses to compete.
The North Vietnamese military (also known as the Vietcong) tactics made it difficult for the United States to defeat them because:
A) They did not wear uniforms- This made it challenging for the United States military to differentiate between who was a citizen and who was a member of the Vietcong.
B) Ambush/Hit and run style of fighting- This military style of fighting can be seen as unpredictable and random. This makes it so that the US military has to be on high alert at all times.
President Ronald Reagan's policies had a positive effect on the country overall. He had a plan for the country's economy that included cutting taxes, deregulation, and reducing the size of government. Because of his policies, he was able to be re-elected and help America improve further.