Refer to the exhibit. A network engineer is deploying SNMP configuration on client's routers. Encrypted authentication must be included on router 1 to provide security and protect message…

The `snmp-server host` command is used to specify the NMS host to which traps/informs are sent and refers to a pre-configured user for authentication, it does not configure the user's authentication or confidentiality parameters on the router itself.

The `snmp-server user` command is used to configure an SNMPv3 user. By including `v3 auth md5 testpassword`, the engineer is enabling authentication for the user `testuser` using the MD5 protocol and a specified password, which is a necessary step for encrypted authentication in SNMPv3. To additionally provide message confidentiality, the `priv` keyword with a privacy protocol (e.g., `des` or `aes`) and its password would also need to be specified in this command.

The `snmp-server group` command defines an SNMPv3 group and its security model, but it does not define individual users, their authentication details, or confidentiality settings, which are crucial for the problem's requirements.

`snmp-server community public` configures an SNMPv1/v2c community string, which provides no encryption for authentication or message confidentiality, directly contradicting the requirement for 'encrypted authentication' and 'message confidentiality.'