Step 1: Understanding the status of Psilotum nudum.
Psilotum nudum is a primitive, vascular plant and is classified as an endangered species. It is rare in the wild and is threatened due to habitat loss.
Step 2: Analyzing the options.
(A) endangered: Correct. Psilotum nudum is considered an endangered species due to its limited distribution.
(B) rare: Incorrect. Although rare, it is classified as endangered rather than just rare.
(C) extinct: Incorrect. Psilotum nudum is not extinct; it is still found in certain areas.
(D) exotic: Incorrect. Psilotum nudum is not considered an exotic species.
Step 3: Conclusion.
The correct answer is (A) endangered, as Psilotum nudum is considered an endangered species.