The correct answer is b) Hayes becomes president and Reconstruction ends.
Reconstruction refers to the 12 years after the Civil War (1865-177). This era was one in which the Confederate States began to rejoin the Union under certain circumstances (like abolishing slavery, giving African-American men the right to vote, etc.). However, this era of increased rights for African-Americans was shortened thanks to the Compromise of 1877. Thanks to this deal, the federal governments regulation of Southern states and their treatment of African-American citizens reduced drastically, allowing Southern states to implement laws that limited the rights and freedoms of newly freed slaves.