Step-by-step explanation:
1. A) It was a foreign policy warning against European intervention in the Americas; 1823. The Monroe Doctrine was a significant foreign policy statement made by President James Monroe in 1823, warning European powers not to interfere in the affairs of independent nations in the Americas.
2. B) Erie Canal. The Erie Canal connected the Great Lakes to the Atlantic Ocean and had a significant impact on trade and transportation in the United States during the 19th century.
3. A) Protective tariffs, national bank, and canals; Promote westward expansion. Henry Clay's American System included protective tariffs to promote domestic industry, a national bank to stabilize the economy, and investments in canals and infrastructure to facilitate westward expansion and economic growth.
4. C) An economic transformation marked by industrialization and increased trade. The Market Revolution in the United States during the 19th century was characterized by significant economic changes, including industrialization, increased trade, and the shift from agrarian to industrial economies.