I want to know the answer to the following question:
Nusach Ari is used by whom?
All the background I'm provided with is that "Two other major forms of nusach among Ashkenazic Jews are Nusach Sefard (not to be confused with the Sephardic ritual), which is the general Polish Hasidic nusach, and Nusach Ari, as used by Lubavitch Hasidim.". Is that enough to answer the question?
Answer: yes