Given the code fragment:
List list1 = Arrays.asList(10, 20);
List list2 = Arrays.asList(15, 30);
//line n1
Which code fragment, when inserted at line n1, prints 10 20 15 30?
Stream.of(list1, list2).flatMap(list -> list.stream()).forEach(s -> System.out.print(s + “ “));
Stream.of(list1, list2).flatMap(list -> list.intStream()).forEach(s -> System.out.print(s + “ “));
list1.stream().flatMap(list2.stream().flatMap(e1 -> e1.stream()).forEach(s -> System.out.println(s + “ “));
Stream.of(list1, list2).flatMapToInt(list -> list.stream()).forEach(s -> System.out.print(s + “ “));
Submit