Final answer:
The integral part of Henry Clay's American System was c) Protective Tariffs, which aimed to protect American industries and support economic growth through a national economic policy.
Step-by-step explanation:
Henry Clay coined the phrase "American system," which was an integral part of his economic development plan during the presidency of John Quincy Adams. The American System included high tariffs, a national bank, and federally sponsored internal improvements such as canals and roads. Among the options provided, the integral part of Clay's American System was c) Protective Tariffs. These protective tariffs were designed to shield emerging American industries from foreign competition, encourage the growth of domestic manufacturing, and generate revenue for the government. The American System was a nationalistic economic policy aimed at improving the country’s financial stability, infrastructure, and self-sufficiency.