What is output by running this DSTester program? import java.util.Arrays; public class DSTester { String[] items = new String[7]; int numItems = 0; int index1 = 0, index2 = 0; public static void main(String [] args) { DSTester ds = new DSTester(); ds.insert(""+13); ds.insert(""+33); ds.remove(); ds.insert(""+4); ds.insert(""+11); ds.insert(""+27); System.out.println( Arrays.toString(ds.items)); public void insert(String item) { index2++; if (index2 >= items.length) index2 = 0; items[index2] = item; numItems++; public String remove() { if (numItems= items.length) index1 = 0; numItems--; return item; m O [4,11,13,27,33] O [13, 33, 4, 11,27] O [13, 33, 4, 11, 27, null] O [null, 13, 33, 4, 11, 27, null] 0 [null, 13, 33, 4, 11, 27]