Answer: B) Manifest Destiny.
James K. Polk, in full James Knox Polk, (born November 2, 1795, Mecklenburg county, North Carolina, U.S.—died June 15, 1849, Nashville, Tennessee), 11th president of the United States (1845–49). Under his leadership the United States fought the Mexican War (1846–48) and acquired vast territories along the Pacific coast and in the Southwest. (For a discussion of the history and nature of the presidency, see presidency of the United States of America.)
After building a successful law practice in Tennessee, Polk was elected to the state legislature (1823) and then to the United States House of Representatives in 1825, becoming a strong supporter of Andrew Jackson. After serving as chairman of the Ways and Means Committee, he became Speaker in 1835, the only president to have been Speaker.
Explanation:
