Which government entity did jackson challenge as president? a. congress b. the vice presidency c. the supreme court d. the national bank

Jackson challenged The National Bank as president.

The 1830s were a tumultuous decade for America. The attempt by the Second Bank of the United States for an early recharter was passed by Congress in July 1832, but the bill was vetoed shortly thereafter by President Andrew Jackson. The hopes of the bank's supporters to turn the veto in a winning campaign issue in that fall's presidential campaign failed dismally. In 1833, Jackson retaliated against the bank by removing federal government deposits and placing them in "pet" state banks. As federal revenue from land sales soared, Jackson saw the opportunity to fulfill his dream of paying off the national debt - which he did in early 1835. But as the economy overheated and so did state dreams of infrastructure projects. Congress passed a law in 1836 that required the federal surplus to be distributed to the states in four payments. Shortly thereafter, the Jackson Administration declared in its "Specie Circular" that payments for federal land purchases be made in specie. When combined with loose state banking practices and a credit contraction, a major economic crisis was brewing when Martin Van Buren took office as president in March 1837. Two months later, New York City banks suspended specie payments. A major economic recession was soon underway. Van Buren - under pressure from his mentor Jackson - decided not to suspend the Specie Circular. Instead, he proposed a set of economic proposals that September - the most of important of which - an independent Sub-Treasury - Congress refused to pass. As a result, the recession double dipped in 1839 and the national economy did not recover until 1843.

Therefore your answer is,

The National Bank.