Why did missions continue to spread throughout california?

Based on the information you were just given, which of the following would make the best topics for your body paragraphs?

The development of simple stone tools by early hominids led to the ability to procure meat more efficiently. this in turn led to the change in diet that included larger amounts of protein. many scholars believe that this shift in diet was a significant part of how our ancient ancestors adapted so quickly to a varied set of environments, and thus were able to begin cultural development. this demonstrates the intimate connection between

This is for my social studies guide and i can answer 21/22 of it perfectly fine. but can someone tell me what the caste system was, and what divisions/classes that it was apart of it?