How the french challenged the monroe doctrine in 1861

After Mexican debts were paid, all countries but France left.

France ignored the Monroe Doctrine and Napoleon III overthrew the Republic of Mexico.

Took advantage of the Civil War.

ummm? is that supposed to be a question or a but this is a reason he won re-election

explanation:

"despite progress in the war, lincoln and most political pundits were convinced that he would lose his bid for reelection in 1864. the country was war weary and the democratic party's nominee, george mcclellan, was likely to negotiate a peace treaty with the confederacy if elected." - loc.gov

i am sure the answer is d