Protected View Saved to this PC- Search es Mailings Review View Help ntain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing 4 18. The text's link-based queue is being used and holds an empty queue. We can say: [1] at this point in time an invocation of the enqueue method would throw an exception. [2] at this point in time an invocation of the dequeue method would throw an exception. [3] the value of front is -1. [4] the numElements variable is null. 19. A glass queue is like a queue but: [1] it uses priorities. [2] it allows enqueuing and dequeuing from both front and rear. [3] it keeps its elements sorted. [4] it allows peeking at front and rear elements. 20. Recall that the Counter class initializes itself to 0, and allows a client to increment it. Identify the possible output of the following code sequence: Counter c = new Counter(); c.increment (); c.increment (); c.increment (); System.out.println(c); I [1] [2] 1 [3] 2 [4] 3 Bonus Questions