Suppose a Java linked list implementation contains a reference to the first node (head), a reference to the tail (last node), an integer that tracks the number of items in the list, two references to nodes that record the cursor position and the predecessor of the cursor position, respectively, and no other instance variables. Which one of the following operations can have an O(1) implementation for a doubly-linked list, but cannot be implemented in better than O(n) time for a singly-linked list?

Group of answer choices

Insertion of an item immediately before the position of the cursor.

Deletion at the beginning of the list.

Insertion at the end of the list.

Deletion at the end of the list.

Insertion at the beginning of the list.

Insertion of an item immediately after the position of the cursor.