Whichever one your device has. Its a technology that google licenses out. If you are making a device that has a secure enclave you can apply for a license for level 1 widevine.
If indeed level 1 has been breached, presumably it happened via one of those weaker secure enclaves.
I'd just like to take a second to appreciate the irony/oxymoron of there being weaker "secure" enclaves
...and the idea of a secure computer in general...