Which of the following is a typical fuel type?

Natural gas is commonly used as a fuel type in residential and commercial heating systems due to its high efficiency and lower emissions compared to other fossil fuels. It is delivered through a network of pipelines, making it readily available in many areas, and is preferred for systems such as furnaces, boilers, and water heaters. Its clean-burning characteristics also make it an environmentally friendlier option for energy use in buildings.

Other fuel types, while utilized for specific applications, may not be as standard in typical building heating systems. Gasoline, for instance, is primarily used in vehicles and not commonly for stationary heating. Wood, although a traditional fuel source, is often considered less efficient and is associated with higher emissions. Kerosene has applications in some heating systems, particularly where natural gas is not available, but it is less commonly used compared to natural gas in modern buildings.