Need help on this one

Consider the following four recursive methods, each of which implements the detection of a palindrome. Input arguments are: a: An array of characters . x and y: The indexes of the elements of the array a. . Initially x = 0 and y = a.length - 1. public static boolean pall (char a, int x, int y){ if (x >= y) return true; if (a [x] = = =[y]) return(po/1(a, x+1, y-1)); else { return false; public static boolean pal2(char a, int x, inty) boolean palindrome = true; f (x >= y) return true else { if (a [x] = = =) return(pol2(a, x+1, y-1)>: else{ palindrome = false: return palindrome: public static boolean pal3(char a, int x, inty)( f (x >= y) return true: if (a[x] == =) return(pa/3(a, x+1, y-1)); return false; public static boolean pal4(char a, int x, inty)( boolean palindrome = true; f (x >= y) palindrome = true; else { if (a[x] == =) pol4(a, x+1, y-1); else { palindrome = false; return palindrome; return palindrome; Each method returns true if the array of characters is a palindrome and returns false otherwise. For example, if a = {u, v. w, w, v, u} it returns true. And, if a = {u, v, w, u, v, u} it returns false. Initially, x is 0 and y is a.length - 1. For example, the method pal1 is invoked by the following statement: po/7(a, 0, a.length-1), where a is an array of characters. Other three methods are invoked in the same way. Note that not all four methods are correct. Which methods are correct? Choose all that apply. O a. Method pall O b, Method pal4 Method pal2 O d, Method pal3