Answer:
back
Explanation:
queue is the data structure which perform operation in particular order. the order is first in first out (FIFO).
it means the element which comes first, remove first.
front: it is used to fetch the first element or oldest element in the queue.
back: it is used to fetch the last element or newest element in the queue.
pop: it is used to remove the first element or oldest element in the queue.
push: it is used to insert the element at the back in the queue.
Therefore, the back is the correct option.
