Which of the following, if true, would best support the author's statement that hot-spot activity may explain the mutability of continental plates? A. Hot spots move more rapidly than the continental and oceanic plates. B. Hot spots are reliable indicators of the age of continental plates. C. Hot spots are regions of volcanic activity found only in the interiors of the continental plates. D. The alignment of hot spots in the Pacific Ocean parallels the alignment of Pacific Ocean islands. E. The coastlines of Africa and South America suggest that they may once have constituted a single continent that ruptured along a line of hot spots.