Final answer:
The examples provided best illustrate the realistic conflict theory of prejudice, which suggests that prejudice arises when groups compete for limited resources.
Step-by-step explanation:
The examples provided, such as anti-Chinese prejudice in the US after the completion of the transcontinental railroad, and anti-Mexican prejudice in the US during times of scarce agricultural jobs, best illustrate the realistic conflict theory of prejudice.
This theory suggests that prejudice arises when groups compete for limited resources, leading to hostility and negative attitudes towards outgroups. In each of these examples, there was perceived competition for jobs or resources, which fueled prejudice towards the respective groups.
Other examples in the question also demonstrate aspects of prejudice, but the focus on competition and scarcity of resources aligns most closely with the realistic conflict theory.