Which of the following is an assumption on which the argument above depends? A. The growth of new rings in a tree is not a function of levels of precipitation. B. Only the Brazilian ash loses rings because of excessive heat. C. Only one day of temperatures above 95 degrees Fahrenheit is needed to cause the Brazilian ash to lose a ring. D. The internal rings of all trees are of uniform thickness. E. The number of rings that will be lost when the temperature exceeds 95 degrees Fahrenheit is not predictable.