President james buchanan a. opposed the expansion of slavery into new territories. b. was a founder of the republican party. c. was committed to states' rights and believed that to save the union concessions must be made to the south. d. was nominated for president by the free soil party in 1856.

Right choice:

c. He was committed to states' rights and believed that to save the Union concessions must be made to the South.

Explanation:

President James Buchanan tried to preserve the unity of the Union by different means but he wasn´t succesful in assuaging rising tensions North-South. He tried to prevent anti-slavery agitation in the North. He enforced the Fugitive Slave Act. Southern states began to secede in his last months in office, spurred by the victory of Abraham Lincoln in the 1860 presidential  election.

there has only been 12 presidents. the 12th president is/was moon jae-in

the anwser is a) to prevent military conflict