Final answer:
Fracking is most closely associated with natural gas as it is a method used to recover gas and oil from shale by creating fractures in the rock.
Step-by-step explanation:
Fracking, also known as hydraulic fracturing, is most closely associated with natural gas. Fracking is a method used to recover gas and oil from shale by drilling down into the earth and directing a high-pressure mixture of water, sand, and chemicals into the rock. This process creates new fractures in the rock, allowing the gas and oil to flow.