Which command is used to save the running configuration to NVRAM?

Both commands, "copy run startup" and "write memory," are classic Cisco commands used to save the current running configuration to non-volatile random-access memory (NVRAM).

The command "copy run startup" explicitly specifies the source as the running configuration and the destination as the startup configuration stored in NVRAM. It's a clear way to indicate the action of copying configurations and is often preferred for clarity.

The command "write memory" accomplishes the same task but is a legacy command, which has been used traditionally in various Cisco devices to save the current configuration without needing to specify the exact source and destination.

The option that includes both commands correctly acknowledges that both are valid methods to achieve the goal of saving the running configuration to NVRAM, thereby reinforcing an understanding of different ways to accomplish the same task in Cisco IOS.