Carefully read the following implementations to answer the questions that follow. public static int F(int x, int Y) { if(Y==0) return 0; return X+F(X,Y-1); } public static int F(int x, int Y) { return F(X,Y,0); } public static int F(int X, int Y, int result) { if(y==0) return result; return F(X, Y-1, result+X); (a) (b) Question 2 2 pts What do these code snippets represent? Select all that apply. O (a) head recursion, (b) tail recursion o iterative methods O recursive methods o (a) tail recursion, (b) head recursion