The best answer to the question is C. passing the 1937 “Anti-Okie Law,” which prohibited California natives from helping migrant workers enter the state.
This statement is incorrect as there was no specific "Anti-Okie Law" that prohibited California natives from helping migrant workers. While there were indeed various actions taken by Californians to resist migrants during the Dust Bowl era, such as the other choices listed, an outright law prohibiting aid from Californians to migrants does not exist in the historical record.