<em>C. Congress could only change the amendments regarding slavery with the unanimous approval from all the states is the correct answer.</em>
Explanation:
Crittenden compromise was the legislation introduced by Kentucky Senator John J. Crittenden for resolving the secession crisis of southern states. It included four congressional resolutions and six constitutional amendments for appeasing the southern nations and to end the civil war. This plan was supported by the southern leaders but got rejected by the northern Republicans. The amendments denied the abolition of slavery in the slave holding states, restored the Missouri Compromise line and compensated the owners of runaway slaves. <em><u>One of the amendments even promised that the future proposals would not be able to alter the five amendments of the Critternden's proposal. </u></em>
