Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out?

Correct Answer: Option A — Secure and tag the supply circuit breaker in the open position.

Title 46 CFR Subchapter J mandates strict electrical safety protocols. Securing and tagging supply circuit breakers in the open position enforces Lockout/Tagout (LOTO) procedures, preventing accidental energization and protecting personnel from severe electrical shock during maintenance.