Which of the following is a run-on sentence?

Example:  I thought about what he'd said soon I realized he was right.

in the quotation from passage, connie willis states that literature is a way for authors from the past to communicate with readers of today. we can read their stories, books, and other texts to learn lessons about life. willis refers to these lessons as messages “from beyond the grave.” willis has a favorable viewpoint about the timelessness of literature.

one context clue that me find the meaning of luxuriance was that the base word of luxuriance is luxury, so i think that luxuriance means something that is luxury, or something luxurious.