Final answer:
The most appropriate title for the box regarding campaign platforms and historical provisions would be the 'campaign platform of Alexander Stephens.' The admission of Kansas as a free state was not part of the Compromise of 1850, and the Dred Scott decision affected the spread of slavery and the citizenship status of Black people.
Step-by-step explanation:
The best title for the box concerning a political platform that involved both proslavery and antislavery elements from the convention would be campaign platform of Alexander Stephens.
Regarding the components of the Compromise of 1850, the option that was not a component is B: the admission of Kansas as a free state. The Compromise included the passage of the Fugitive Slave Act, the admission of California as a free state, and a ban on the slave trade in Washington, D.C. Kansas was not admitted as a free state during the Compromise of 1850; that issue was later addressed with the Kansas-Nebraska Act in 1854.
The Dred Scott v. Sandford decision proclaimed that Congress had no authority to stop or limit the spread of slavery into American territories and stated that Black people were not citizens and therefore could not sue in federal courts.