You are correct, the answer A) fire has been known to flash back over the surface of an oil fire is the correct answer. The reasoning is that regular dry chemical (sodium bicarbonate) extinguishers are not recommended for fighting fires involving flammable liquids like oil. The sodium bicarbonate powder can cause the fire to flash back over the surface of the oil, reigniting the fire. This is due to the way the dry chemical works, as it creates a thick, insulating foam that can be easily disturbed, allowing the fire to reflash. The other options are incorrect because: B) is incorrect as dry chemical extinguishers are effective on high-voltage electrical fires, C) is incorrect as sodium bicarbonate does not significantly decompose under normal storage conditions, and D) is incorrect as sodium bicarbonate does not emit noxious fumes when heated.