Given a non$-$empty queue initially containing the elements $1,3,6$ with $1$ at the

front and $6$ at the rear. Perform the following sequence of operations:

dequeue $()$

dequeue $()$

enqueue $(5)$

enqueue $(2)$

dequeue $()$

What elements are left in the queue from front to rear after completing the above

operations?

$1,5$

$2,5$

$5,6$

$5,2$