Which of the following is a characteristic of Primary Fires?

• A. Grassland fires
• B. All fires in buildings and vehicles that are not derelict or in outdoor structures
• C. Fires in derelict buildings
• D. Indoor office fires

Answer: (B)

Primary fires are the ones that occur in locations normally in use where people may be present and at risk. They happen in buildings and in vehicles that are not derelict and are not outdoor structures.

That makes the described option the best fit: it specifies fires in buildings and vehicles that are not derelict or in outdoor structures, which covers typical occupancies like offices, shops, factories, and vehicles. Grassland fires happen outdoors with no occupancy, derelict buildings are not in use, and fires in indoor offices are included because they occur in a non-derelict building, aligning with the definition.