Explanation:

Correct: Furnace oil is a residual product obtained from the distillation of crude oil in refineries. It's a heavy oil and is also referred to as fuel oil or bunker fuel.

Incorrect: While furnace oil can be used as fuel in certain industries for power and heat generation, it is not typically the primary source for power generation, especially when considering large-scale power plants that primarily use coal, gas, or other renewable sources.

Correct: Furnace oil, especially if it's of lower quality, can have high sulfur content. When burned, it can release sulfur dioxide (SO2) into the atmosphere, which can contribute to acid rain and respiratory problems in humans.