I need some help, it's emotion

How does this passage contribute to the overall meaning of the story

However, the idea of real-life people living in what would become the united states for thousands of years before columbus ever left spain never dawned on me. what would be the best way to revise this sentence for greater clarity? a) however, the fact that columbus left spain thousands of years after people settled what would become the united states never dawned on me. b) it never dawned on me, however, the idea of real-life people living in what would become the united states for thousands of years before columbus ever left spain. c) however, the fact that people were already living in what would become the united states for thousands of years before columbus ever left spain never dawned on me. d) however, the idea never dawned on me that long before columbus ever left spain, real-life people lived for thousands of years in what would become the united states.

Athesis statement is not a.a question; it is your answer to a research question that you will address in your essay b.your position on a topic you will address in your persuasive essay c.about the topic of your persuasive essay.it is about the opposite position