The author implies which of the following about Geology as a science? A. its legitimacy as a scientific discipline is not well established B. its proper field is Earth, and therefore its analyses of other planets and moons is more speculative C. it did not find, in previous religious models of the Earth, a sound basis for analytical theories D. it can deduce everything about the surface of Mercury purely from Earth-based observations E. its success derives from surviving exposure to major catastrophes