The correct answer is B. Readmitting states when 10 percent of the electorate took a loyalty oath.
Explanation:
The election of Abraham Lincoln as the President of the U.S. motivated states of the South to secede from the United States and began the Civil War, which was influenced by the slavery issue. In this context, one of the purposes of Lincoln was to end slavery and re-integrate states of the South.
This was possible only at the end of the Civil War. Moreover, the plan Lincoln implement was known as the Ten percent plan and involved the 10% of the people who could vote in a state (electorate) needed to take a loyalty oath or declare complete loyalty and support to the U.S. government for the state to be admitted in the U.S. again.
