A drive speed reference fluctuates after the analog cable shield is landed on the signal common at both the drive and PLC end. What should be checked?

1. AThe motor nameplate current because current determines analog shielding.
2. BThe drive fan speed because it creates speed-reference commands.
3. CReview shield termination, signal common reference, grounding noise, cable routing, and input filtering.
4. DThe keypad password level before checking analog wiring.