Queues are useful in situations where: elements must be processed immediately O we must deal with postponed obligations. O items are processed in the order they are encountered O sorting is required. O None of these is correct. 3. Assume you are using the text's array-based queue and have just instantiated a queue of capacity 10. You enqueue 5 elements and then dequeue 2 elements. Which indices of the internal array elements hold the remaining elements? o to 2 1 to 3 2 to 4 O to 4 7to9