Office pro 2021 can be purchased on the internet for under $40. Legit copies
#7 is correct. I bought the Full version of Office 2021 at $35 last Dec 2022. You have to have Windows 10 or 11.
CNET https://www.cnet.com/deals/save-over-400-on-an-office-pro-2021-license-at-stacksocials-deal-days-sale/