Natural gas a. is transported primarily by truck and rail b. was discovered by m. king hubbert in 1885 c. can be extracted via hydrofracking d. will be depleted by 2030 at current usage ratese. consists primarily of octane

Option (C)

Explanation: Hydro-fracking is a process by which the natural gas can be taken out by drilling down into the earth before injecting a high pressure fluid or a water-mixture. It is an efficient and a cheaper method and but sometimes oil seeps through the fractures, which could probably harm the environment.

Thus the correct answer is option (C).