The correct answer is: C. Butane
LPG is a mixture of propane and butane, which are both liquefied petroleum gases. Propane has a boiling point of -42 degrees Celsius, while butane has a boiling point of -0.5 degrees Celsius. This means that both gases will liquefy at room temperature if they are pressurized.
Hydrogen has a boiling point of -252.87 degrees Celsius, while oxygen has a boiling point of -182.96 degrees Celsius. This means that both gases will remain in a gaseous state at room temperature, even if they are pressurized.
Methane has a boiling point of -161.5 degrees Celsius. This means that methane will liquefy at room temperature if it is pressurized, but it will not liquefy at atmospheric pressure.
Therefore, the only option that is a liquefied petroleum gas is butane.