After inserting a node at the end of a circular singly linked list using a tail pointer, which statement is true about the tail pointer?

• A. Tail pointer remains pointing to the old tail.
• B. Tail pointer is updated to point to the new node.
• C. Tail pointer becomes null.
• D. Tail pointer points to the head.

Answer: (B)

In a circular singly linked list, the tail pointer is meant to always refer to the last node in the circle and its next pointer points back to the head. When you insert a node at the end, you link the new node after the current tail, have the new node point to the head (which is the current tail’s next), and then move the tail pointer to the new node. This updates the tail to the new end of the list, preserving the circular structure. So the tail pointer becomes the new node. The other options don’t fit because the tail should reflect the new last element, the list isn’t emptied by an insertion, and while the tail’s next continues to point to the head, the tail itself should point to the new node, not the head.