Converting from LLC to Sole Proprietorship: Which business name do I put on Schedule C?

I am converting my single-member LLC to a Sole Proprietorship in March 2022. When filing my 2021 return, which business name should I put in box C, "Business name" of Schedule C? Should I use the EIN associated with my new Sole Proprietorship, or should I use the EIN that was issued to my now-dissolved single-member LLC?

Any help would be much appreciated, thank you!