Which commands are used to enable SSH and Telnet access on a Junos device?

Enabling SSH and Telnet access on a Junos device involves configuring system services that facilitate secure and unencrypted access to the device. The correct commands, "set system services ssh" and "set system services telnet," are part of the Junos operating system's configuration syntax, which focuses on system-level configurations.

By using these commands, you instruct the device to allow incoming SSH and Telnet connections. SSH provides a secure method for remote management and configuration, while Telnet is a simpler protocol without encryption, suitable for use in secure or trusted environments.

The other options do not align with the Junos command structure. For example, "enable service" and "configure service" do not match the syntax rules of Junos, which consistently uses "set" for enabling services within the system hierarchy. Additionally, the mention of "junos" in another option is incorrect, as the services are configured directly under the "system" level rather than a specific "junos" context. Thus, the initial choice properly reflects the correct and required commands for enabling these two access methods on a Junos device.