Reconstruction refers to the process by which . a. African Americans were elected to Congress b. states that had seceded were brought back into the Union c. Andrew Johnson became president following Lincoln’s death d. schools throughout the North were rebuilt

b

Explanation:

military occupation of the South to implement the Reconstruction

B is the answer

Explanation:

d. it adversely affected american productivity

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;