Answer: B.They show that nature is guiding the turtle.
In this excerpt, the author discusses the life cycle by using the turtle as a character. He states that the turtle thinks of a gate "through which her life keeps walking." The poem shows how natural events (such as death, birth and life) dominate our lives. Moreover, he connects this message with the poem by telling us how the dream is not actually the turtle's but that it came to her "in the rain or the soft wind," emphasizing the power of nature even more.