What is the initial state of a linked list when no nodes are present?

• A. Both head and tail pointers are nullptr
• B. Head and tail point to the same dummy node
• C. Head is non-null and tail is null
• D. Both head and tail point to new nodes

Answer: (A)

When a linked list has no nodes, both the head and tail pointers are nullptr. This clearly signals emptiness: there is no first node to reference, and there is no last node to reference either. Keeping both pointers null also makes insertion and other operations straightforward—when you add the first node, you set both head and tail to that new node, establishing a non-empty list from a clean empty state.

Other options assume a non-empty structure or a dummy node. Pointing head and tail to the same dummy node changes the interpretation of an empty list, and having head non-null with tail null would be inconsistent, since a non-null head implies at least one node. Pointing both to new nodes would mean the list already contains elements, not an empty list.