how to answer the following questions The number of recursive calls that a method goes through before returning is called:  A. order of growth efficiency.  B. the depth of recursion. C. combinatorial recursive count. D. activation stack frame.   The following code is supposed to return the sum of the numbers between 1 and n inclusive, for positive n. An analysis of the code using the "Three Question" approach reveals that: int sum(int n){   if (n == 1)     return 1;   else     return (n + sum(n)); } A. it fails the base-case question.  B. it fails the smaller-caller question. C. it fails the general-case question. D. it passes on all three questions and is a valid algorithm.   If we cannot remove recursion because tail recursion does not exist, we can always remove it by using:  A. statically allocated activation records  B. a dynamic programming approach.  C. our own explicitly declared stack.  D. a carefully constructed loop

Do the trace in detail and submit  The source Code As Well From the following recursive method Trace (in details) the calling of the above method with any input from your choice such that thereturned value will be 19. public static int think(int x) {if(x<10)if(x%2!=0)return x;elsereturn 0;elseif(x%2!=0)return x%10 + think(x/10);elsereturn think(x/10);}

The following recursive method called z is created. This method accepts two parameters: A string s, and an integer index  The code in the method is:      if (index == s.length())        return "";          <------ base case     if(index % 2 == 0)        return ""+ s.charAt(index) + z(s,index+1);           <---- recursive call     else        return z(s,index+1);             <----- recursive call   What would be the output with the call:   z("javajavajava",0);

I need the code from start to end with no errors and the explanation for the code ObjectivesJava refresher (including file I/O)Use recursionDescriptionFor this project, you get to write a maze solver. A maze is a two dimensional array of chars. Walls are represented as '#'s and ' ' are empty squares. The maze entrance is always in the first row, second column (and will always be an empty square). There will be zero or more exits along the outside perimeter. To be considered an exit, it must be reachable from the entrance. The entrance is not an exit.Here are some example mazes:mazeA7 9# # ###### # #   ## # # #### #     ## ##### ##       ########## RequirementsWrite a MazeSolver class in Java. This program needs to prompt the user for a maze filename and then explore the maze. Display how many exits were found and the positions (not indices) of the valid exits. Your program can display the valid exits found in any order. See the examples below for exact output requirements. Also, record…