Which of the following is a natural gas?

Liquefied petroleum gas, also known as LPG, LP gas, or condensate, is a fuel gas that typically comprises combustible mixtures of propane, butane, and propylene. The latter two, however, often make up 5% or less of the mixture. LPG is a fuel gas used in cars, cooking appliances, and heating appliances. In an effort to lessen harm to the ozone layer, it is being used more and more as a refrigerant and an aerosol propellant. It is frequently referred to as autogas when used specifically as a fuel for vehicles.

Methane (CH4) makes up the majority of compressed natural gas (CNG), which is a fuel gas that is compressed to less than 1% of its volume at regular atmospheric pressure. It is typically cylindrical or spherical in shape and stored and distributed in rigid containers at a pressure of 20–25 MPa (2,900–3,600 psi). Traditional petrol/internal combustion engine cars that have been modified or those that were made particularly for CNG use CNG, either exclusively (dedicated), in conjunction with another fuel (dual fuel), or both (combined) (bi-fuel). Diesel, gasoline, and liquefied petroleum gas can all be substituted for it (LPG). In comparison to the aforementioned fuels, CNG combustion emits fewer harmful gases.