Read the excerpt from The Dark Game: True Spy Stories from Invisible Ink to CIA Moles.
Yet, by the time Robert E. Lee surrendered to Ulysses Grant at Appomattox, Virginia, some four years later, about 620,000 soldiers had died on the battlefields, more than American battle deaths in all other wars from the Revolution through the Vietnam War.
What is the author’s primary purpose for including this detail?
A. to inform readers about the differences between three military conflicts
B. to persuade readers of the seriousness of the American Civil War
C. to entertain readers with tales from behind the lines of battle
D. to encourage readers to visit battlegrounds in Appomattox, Virginia

B. to persuade readers of the seriousness of the American Civil War.

Explanation:

In the excerpt from "The Dark Game: True Spy Stories from Invisible Ink to CIA Moles" A comparison between the number of soldier's deaths in the American Civil War, and in other wars from the Revolution via the Vietnam War can be seen. The purpose of the author to include this detail is an deliberate attempt to persuade and convince the readers of the seriousness and the aftermath of the American Civil War.

B. to persuade readers of the seriousness of the American Civil War

Explanation:

the statement that best explains why the tenth amendment reserves some rights and powers to states is that the framers believed in the principle of federalism. this principle says that some powers are in the hands of a centralized national government, while others are reserved for the governments of several states.