The statement that BEST explains why Reconstruction ended is:
B Enforcement of Reconstruction Acts decreased because of political compromise.
This response highlights the role of political compromise, particularly the Compromise of 1877, which effectively ended Reconstruction by withdrawing federal troops from the South in exchange for resolving the disputed 1876 presidential election. This led to a reduction in enforcement of the Reconstruction Acts and ultimately allowed Southern states to implement Jim Crow laws and disenfranchise African Americans.