Which action is routinely performed at the annual servicing and inspection of a dry-chemical cartridge-operated portable fire extinguisher?

Correct Answer: Option B — Inspect and weigh the cartridge.

Cartridge-operated extinguishers rely on a pressurized gas cartridge to expel the dry chemical. Annual servicing requires weighing the cartridge to ensure the propellant charge has not leaked over time, verifying that the extinguisher will function correctly when the trigger is pulled during an emergency situation.