What are the most important full forms? (Like- NASA)

Read his first two lines from edgar allan poe is the reason once upon a midnight dreary while i pondered weak and weary over and then you’re clean and curious volume of forgotten lore which of these best describes the tone in these lines

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.

The pilgrims are at in the beginning of the prologue.