Answer:
natural gas
Step-by-step explanation:
Natural gas is the fossil fuel which can be stored underground due to the fact that, it is easily evaporated when exposed to the air. To prevent its loss due to exposure, there is need to store it below its normal temperature thereby liquefying it (making it to exist as a liquid rather than gas). Also, transportation through the pipelines helps in its protection rather than open transportation using trucks due to its high volatile nature.