The author of the passage implies which of the following in discussing the development of philosophy during the nineteenth century? A. Nineteenth-century philosophy took science as its model for understanding the bases of knowledge. B. The role of academic institutions in shaping metaphysical philosophy grew enormously during the nineteenth century. C. Nineteenth-century philosophers carried out a program of investigation explicitly laid out by Descartes and Spinoza. D. Kant had an overwhelming impact on the direction of nineteenth-century philosophy. E. Nineteenth-century philosophy made major advances in understanding the nature of knowledge.