Option B makes more sense here since passwordless authentication is supported for both interactive and service accounts (like User3), but passkey (D) won't work for non-interactive scenarios. D looks tempting but is a trap for service use. Anyone disagree?
I was thinking D makes sense here since FIDO2 passkeys are super secure for logins. Since all three would be covered for strong auth, seemed solid. Not sure if the service account setup would be tricky with this though, so maybe I'm missing something.