public interface Queue { /** * Returns the number of elements in the queue. */ int size(); /** * Tests whether the queue is empty. */ boolean isEmpty(); /** * Inserts an element at the rear of the queue. */ void enqueue(Object e); /** * Returns, but does not remove, the first element of the queue, or null if the queue is empty */ E first(); /** * Removes and returns the first element of the queue, or null if the queue is empty */ E dequeue(); } 

Consider the following sequence of operations on a Queue that begins empty. Give the return value for each line. If it causes an error, then write ERROR.

enqueue("A") B C

enqueue("B")

dequeue() // FIRST

first() // SECOND

enqueue("C")

dequeue() // THIRD

dequeue() // FOURTH

dequeue() // FIFTH

Group of answer choices

FIRST

[ Choose ] true null B A false C

SECOND

[ Choose ] true null B A false C

THIRD

[ Choose ] true null B A false C

FOURTH

[ Choose ] true null B A false C

FIFTH

[ Choose ] true null B A false C