Which of the following best describes the author's presentation of information in the passage? A. A number of experiments are described to support the idea that birds use the Sun and the night sky to navigate. B. The author uses logic to show that the biological clock in birds is inaccurate. C. A structured argument about the importance of internal versus external cues for navigation is presented. D. The opposing points of view about bird migration are clarified through the study of contrasting experiments.