According to the passage, natural gas is a product of _________.

Natural gas is a product of fossil remains. The passage\u2019s first sentence informs you that \u201C natural gas is a mixture of carbon and hydrogen that develops from the fossil remains of ancient plants and animals buried deep in the Earth.\u201D The passage informs you that natural gas is used to make electricity and that the production of natural gas will help lead to the United States\u2019 economic recovery. It also states that natural gas is discovered using a hydraulic fracturing technique.