Answer:
A. A login vty mode subcommand
Explanation:
since we are protecting co-workers from connecting to the switches from their desktop PCs, we would need a Telnet line which is used to connect to devices remotely from other network devices on the same network segment as the device we want to connect to. A login local vty subcommand configures a local username for login access but since our design constraint is to configure without usernames, option A is the correct answer.
I would choose B. exosphere. Astronomers study outer space, planets and ect.
Am sorry what can you be more specific
