All recursive methods have the following characteristic(s): a. The method is implemented using an if-else or a switch statement that leads to different cases. b. One or more base cases (the simplest case) are used to stop recursion. c. Every recursive call reduces the original problem, bringing it increasingly closer to a base case until it becomes that case. d. Recursive methods compare the first and last values of the method. e. The base case is the always the first case calculated. f. The method is implemented using a while loop.