The best sentence that proves Nina is having to adjust to a new place as she is about to begin college is:
C: “As her uncle lifted them off the ground, Nina felt the plane detach from the water, but she knew she was leaving behind more than mere earth” (paragraph 7).
This sentence reflects her realization that she is not just leaving her physical location but also her entire past and the life she has known, indicating a significant adjustment as she prepares to start this new chapter in her life.