Final answer:
The standard feature of Busy Lamp Field (BLF) is to monitor the call status of other extensions, showing whether lines are occupied, ringing, or available, not to provide call handling features like forwarding, waiting, hold, or transfer.
Step-by-step explanation:
The Busy Lamp Field (BLF) is a feature on business telephones that allows the user to observe the call status of other extensions within the same system. A standard feature of BLF is to show whether another line is occupied, ringing, or available. Out of the options provided, BLF is not directly associated with call forwarding, call waiting, call hold, or call transfer. Although these features may be accessible on a business phone system, the key function of BLF is to monitor the status of other phone lines, which assists in managing incoming and outgoing calls more efficiently within an organization.