Final answer:
When Mexico won its independence from Spain in 1821, it was much smaller in area than the United States. The U.S. acquired about 55% of Mexico's territory through the Treaty of Guadalupe Hidalgo in 1848, including California.
Step-by-step explanation:
When Mexico won its independence from Spain in 1821, it was much smaller in area than the United States at the time. The United States gained about 55% of Mexico's territory through the Treaty of Guadalupe Hidalgo in 1848, which included the present-day states of California, Nevada, Utah, and parts of Texas, Arizona, New Mexico, Colorado, and Wyoming.
After Mexico's independence, its leaders did not found new missions in California. Instead, the Spanish had already established religious missions in the 1700s, and these missions continued under Mexican rule. Additionally, Americans did not immediately begin settling in California in large numbers after Mexico's independence. Rather, California became a U.S. state after the discovery of gold in 1848 and the subsequent Gold Rush in 1849. This led to a surge in population and the establishment of an organized government in California.
Therefore, the correct answer is d) it was much smaller in area than the United States at the time.