Which statement best describes how termination and traversal differ between a singly linked list and a circular singly linked list?

• A. In a circular singly linked list, tail.next points to head, so traversal ends when you loop back to the head.
• B. The traversal ends when you encounter a null pointer, same as a singly linked list.
• C. There is no difference between the two types in termination.
• D. Circular lists require a sentinel node to denote the end.

Answer: (B)

The key idea here is that termination depends on the structure of the list. In a standard singly linked list, traversal ends when you reach a node whose next pointer is null, signaling the end of the list. In a circular singly linked list, there is no null terminator because the last node points back to the head, forming a loop. So there isn’t a natural null pointer to stop at. To traverse safely, you start at the head and continue moving to the next node until you return to the head (or you count nodes to stop after visiting all of them). For example, with A -> B -> C and A as the head, you would visit A, B, C, and then stop when you come back to A. That distinction is what changes how termination works between the two structures. The idea that traversal ends at a null pointer describes a linear list, not a circular one, and requiring a sentinel node isn’t a necessity for circular lists—it's just an implementation choice.