Program must be in C.

Please answer all questions.

For this assignment, let's write recursive functions that solve three different problems: l) Determining if a string is a palindrome or not. 2) Printing the characters of a string backwards instead of forwards. 3) Calculating the Greatest Common Divisor (GCD) of two integers. All of these problems should be solved by a separate recursive function. You can determine what the prototypes should be. In all cases, analyze the problem space for two characteristics: (a) what the base case should be, and (b) how a larger problem can be solved by making recursive calls to smaller, but similar problems. That will tell you how to set up the selection logic statement that is necessary in a recursive function. In general, your program should do the following: l) For Problems (1) and (2) above, ask the user to input a character string. For Problem (1), determine whether the string is a palindrome or not by using a recursive function and report the result to the user. For Problem (2), print the string in reverse (also by using a recursive function)