Regarding the diagram's "California Under Spanish Rule" section:
Choice: performed mission work
This assertion fits the historical background of California during the Spanish colonial era. Native Americans were frequently assigned to labor on missions, helping with a variety of jobs like construction, farming, and other manual labor.
The diagram's ideal title is as follows:
Option: California's indigenous people
This title, which focuses on the Native American population and their experiences during many periods, including Spanish rule and maybe beyond, best captures the broad historical background depicted in the diagram.