Final answer:
Jim Fisk and Jay Gould are most associated with 'Black Friday' in 1869, where they tried to manipulate the gold market, leading to a market crash. Option d. is correct.
Step-by-step explanation:
The event most associated with Jim Fisk and Jay Gould is d. Black Friday. These two speculators attempted to corner the gold market by manipulating prices for a profit, utilizing connections like Abel Corbin, a relative of President Ulysses S. Grant. Their scheme led to the catastrophic market collapse on September 24, 1869, known as Black Friday, characterized by the plummeting prices of gold and stocks and the failure of numerous brokerage houses. This event was a significant economic setback, although the nation's economy eventually grew in the years following, particularly in the railroad sector.