How to handle sensors not pluged in and components not comunicating

Hi guys I'm curious on how you guys handle analog values of sensors not plugged in and registers who are not being updated because of failed communication between a PLC and another component (example: PLC communicating with a energy analyser/flow meter/other PLC/VFD by modbus RTU/TCP/Profinet).

Do you:

Exemple A: Keep whatever values of underflow/overflow, old values of registers, present them in the HMI and just create alarms of faulty sensor/faulty communication?

Example B: Move "0" to all values and registers and create alarms of faulty sensor/faulty communication?

Example C: Any other suggestion?