Given the code fragment: List<Integer> list1 = Arrays.asList(10, 20); List<Integer> list2 = Arrays.asList(15, 30); //line n1 Which code fragment, when inserted at line n1, prints 10 20 15 30? 

Answer options:

A. Stream.of(list1, list2) .flatMap(list -> list.stream()) .forEach(s -> System.out.print(s + " "));
B. Stream.of(list1, list2) .flatMap(list -> list.intStream()) .forEach(s -> System.out.print(s + " "));
C. list1.stream() .flatMap(list2.stream().flatMap(e1 -> e1.stream()) .forEach(s -> System.out.println(s + " "));
D. Stream.of(list1, list2) .flatMapToInt(list -> list.stream()) .forEach(s -> System.out.print(s + " "));

A