B. The population explosion that occurred in California after the Gold Rush readied California for statehood sooner than expected, igniting another free state/slave state controversy.
Explanation:
The California Gold Rush led to a population explosion in the region. Many people travelled to California in order to try to make a fortune. While very few people became rich, many people stated in the area and settled there. The rise in population ignited California's claim for statehood. However, every new admission to the union potentially affected the balance of power between slave and free states. This situation reignited sectional tensions in the United States.
