To expand on @schoen’s excellent answer:
Of the certificates your host offers:
- “Rapid SSL” is exactly the same as what Let’s Encrypt offers.
- “True business ID” also does offline business validation, but this isn’t something non-technical visitors see when visiting the site.
- “True business EV” does a more strict offline validation and is shown in the visitor’s browser as a green bar with your legal name.
My personal opinion: use Let’s Encrypt unless you want to want the green bar, which will cost you € 297 a year.