Wellll... that question couldn't be more messed up. (Can't take credit for that one though). It's being changed to the following: QUESTION SHOULD SAY: "Which THREE are true..."
Currently it says correct answers are A and C SHOULD BE: correct answers are A, C, and E New explanation SHOULD BE: ============================ Options A, C, and E are the correct answers. The Set interface does not permit duplicate elements, but since ArrayList implements List and not Set, it can hold duplicates. Its methods are not synchronized, so it's not thread-safe on its own. List classes use a ListIterator rather than a simple Iterator, because a ListIterator lets you traverse bi-directionally. It is well-suited for fast random access, and implements the RandomAccess interface. It also implements java.util.Collection (not Collections with an 's'). ============================ We don't know what happened to that one, but in any case, it's been submitted to be fixed. Thanks! -Kathy responsible for only the questions that are absolutely perfect, correct, cogent, and interesting