The true statement about California is: "Spanish missions were the founding base of many cities."
California is known for its Spanish missions, which were established by Spanish colonizers in the 18th and early 19th centuries and laid the groundwork for many of the state's cities.
The other statements are not accurate: California's nickname is "The Golden State," not "Sunshine State" (which is Florida's nickname), and most cities in California do not have French names; they have names derived from Spanish, Native American, or other influences.