Identify three common ignition sources found in residential occupancies.

• A. Lightning, tsunamis, and solar flares.
• B. Wind gusts and rain.
• C. Electrical malfunctions, unattended cooking, and candles.
• D. Vehicle exhaust only.

Answer: (C)

In residential occupancies, three common ignition sources are electrical malfunctions, unattended cooking, and candles. Electrical malfunctions—like overloaded circuits, frayed cords, or faulty appliances—generate heat or sparks that can ignite nearby combustibles. Unattended cooking is a leading cause because stoves and frying appliances produce intense heat and flames, and leaving them unattended allows fires to start and spread quickly. Candles create open flames that can easily ignite curtains, paper, or other combustibles if left unattended or knocked over.

Other options don’t fit as common residential ignition sources: lightning, tsunamis, and solar flares aren’t typical ignition sources inside homes; wind and rain affect fire spread but aren’t primary ignition sources by themselves; vehicle exhaust isn’t a standard residential ignition source in normal conditions.