What roles did john c. calhoun, henry clay, and daniel webster play in early 19th-century sectional disputes?

HENRY CLAY of Kentucky, JOHN C. CALHOUNof South Carolina, and DANIEL WEBSTER of Massachusetts dominated national politics from the end of the War of 1812 until their deaths in the early 1850s. Although none would ever be President, the collective impact they created in Congress was far greater than any President of the era, with the exception of Andrew Jackson. There was one issue that loomed over the nation throughout their time in power — slavery. They were continuously successful in keeping peace in America by forging a series of compromises. The next generation's leaders were not.

The Gold Rush led to the rapid settlement of California which resulted in its imminent admission as the 31st state. Southerners recognized that there were few slaves in California because Mexico had prohibited slavery. Immediate admission would surely mean California would be the 16th free state, giving the non-slave-holding states an edge in the Senate. Already holding the House of Representatives, the free states could then dominate legislation.

on this day in 1913, henry ford installs the first moving assembly line for the mass production of an entire automobile. his innovation reduced the time it took to build a car from more than 12 hours to two hours and 30 minutes.

i believe your answer is d)