Final answer:
The passage describes the influx of people known as the forty-niners to California during the 1848-49 gold rush, prompted by James Marshall's discovery of gold, and the appropriate title for this passage is 'Who Were the 49ers'. The correct option is d.
Step-by-step explanation:
In 1848, James Marshall discovered gold at Sutter's Mill in California, which led to the massive migration known as the California Gold Rush. People who traveled west in 1849 in hopes of finding fortune and returning with "riches to last a lifetime" were called the forty-niners. This gold rush caused a significant population increase in California, prompting the need for an organized territorial government.
Not all fortune seekers found success; many faced the harsh realities of mining, while others prospered by providing services to the miners.
The best title for the passage about these young adventurers would be 'Who Were the 49ers' as it directly references the group of individuals traveling to California in 1849 seeking gold, making it a fitting summary of the passage's content.
Hence, Option d is correct.