What does the following method do? public static int mystery(int a[], int x) { int c = 0; for(int i = 0; i < a. length; i++) { if (a[i] == x) c++; } return c; } returns a count of the number of elements in the array. returns a count of the number of positive elements in the array. returns a count of the number of times x appears in the array. returns the average of the values in the array. returns the sum of the values in the array.