The following LinkedList operation has similar function as removeFirst().Aremove()Bremove(Object o)Cremove(int index)DremoveFirstNode()

To determine which LinkedList operation has a similar function as removeFirst(), let's analyze each option given:

1. Aremove(): This option does not seem to fit the LinkedList context directly and might be a typographical error, as it isn't a standard method in common implementations.

2. Bremove(Object o): This method removes the first occurrence of a specified element (object) from the list. While it can remove an element, its function is not specifically to remove the first node.

3. Cremove(int index): This method removes the element at the specified index. It does not necessarily operate on the first element unless the index specified is 0, and it's not the same as removeFirst() since it requires the index, rather than a unique operation to remove the first item.

4. DremoveFirstNode(): This method directly suggests the action of removing the first node of the LinkedList, which aligns perfectly with the functionality of removeFirst()—which removes the head element from the list.

Conclusion

The method that has a similar function as removeFirst() is D) removeFirstNode(), as it explicitly indicates removing the first node of the linked list.