Que. 
Consider an implementation of unsorted single linked list. Suppose it has its representation with a head and a tail pointer (i.e. pointers to the first and last nodes of the linked list). Given the representation, which of the following operation cannot be implemented in O(1) time ?

a. 
Insertion at the front of the linked list 
b. 
Insertion at the end of the linked list 
c. 
Deletion of the front node of the linked list 
d. 
Deletion of the last node of the linked list 

Answer:Deletion of the last node of the linked list 