The correct answer is "forty-niners."
Explanation:
1. The term "forty-niners" refers to the people who came to California in 1849 during the Gold Rush seeking to find gold and make their fortune.
2. These individuals were called "forty-niners" because they arrived in California in the year 1849 to participate in the gold rush.
3. The nickname "forty-niners" is specific to this group of individuals who migrated to California during the Gold Rush era in search of gold.
