In raymond's run readers get an inside perspective on squeaky's thoughts and feelings. which best explains how the author achieves this effect

I am pretty sure that in "Raymond's Run," readers get an inside perspective on Squeaky's thoughts and feelings due to the fact that author first-person point of view. When the story is written in such a way it means that story is being described as if it is  being recorded by camera : you observe everything in your own way, and there is no appeal to the reader, just a story as it is.