If Donald Duck says, "All ducks always lie," and his statement is true, then it means that ducks, including himself, always lie. However, if all ducks always lie, then his statement must also be a lie. This creates a paradox, as his statement cannot be both true and false simultaneously. Therefore, we can conclude that his statement is false.
So, the correct statement is: "Donald Duck's statement is false."
Correct Answer: C