Answer:
I think it is all of the above
Explanation:
because if you looked in the video it talked about all of those things. so it is
D. ALL OF THE ABOVE
The main idea of the Trail of Tears in 1838 and 1839 was to force the Cherokee nation to give up its land in the Mississippi river and migrate to present Oklahoma, as part of Andrew Jackson's Indian removal policy, this way the white settlers could grow cotton on the Indians land. It is important to learn about it to enforce the laws and protect the rest of the indigenous civilization in modern days
If you really think about it is Everything from what you eat how you dress and even religion.

A river valley civilization is an agricultural nation or civilization situated beside and drawing sustenance from a river. A "civilization" means a society with large permanent settlements featuring urban development, social satisfaction, specialization of labor, centralized organization, and written or other formal means of communication. A river gives the inhabitants a reliable source of water for drinking and agriculture. Additional benefits include fishing, fertile soil due to annual flooding, and ease of transportation. The first great civilizations, such as those in Mesopotamia and Ancient Egypt, all grew up in river valleys. Tigris River flourished near Mesopotamia civilization and river nile flourished near civilization of Egypt.
<h2>ꜰᴏʟʟᴏᴡ ᴍᴇ❤</h2>
Actually they are right, because in the period in the U.S. history after the Civil War and Reconstruction, lasting from the late 1860s to 1896, is referred to as the “Gilded Age.” This term was coined by Mark Twain and Charles Dudley Warner in their book The Gilded Age: A Tale of Today, published in 1873.