The process of fracking involves a using underground explosives to break up gas-rich shale deposits. b processes that are under the regulation of the 2005 Safe Drinking Water Act. c using coal and petroleum as a chemical basis for producing natural gas. d using high-pressure fluids to fracture gas-rich shale deposits far underground.

D. Using high-pressure fluids to fracture gas-rich shale deposits far underground.

Explanation:

The process of fracking involves

using high-pressure fluids to fracture gas-rich shale deposits far underground so as to force open existing fissures and extract oil or gas. Water, sand and chemicals are injected into the rock at high pressure which allows the gas to flow out to the head of the well.