(1) It can contain duplicates (2) Its methods are thread-safe (3) Can be iterated bi-directionally <-- (4) It implements java.util.Set (5) It is well-suited for fast random access (6) It implements java.util.Collections
Source: "Giri Mandarika" (Link provided in JavaRanch)
How option 3?
Is option 3 talking about ListIterator, because only that can be used to iterate the list bidirectionally?
Is ListIterator in the exam? It is Iterator (with two methods hashNext() and next() as I know), that is discussed in K&B!