Concept:Petroleum is a liquid mineral trapped deep underground, so it cannot be extracted by methods meant for solid minerals.Explanation:Crushing, adit, and open cast methods are used for solid materials such as coal, rocks, or ores.Petroleum is stored in porous rock layers far below the surface.A borehole is made by rotating a drill bit through the Earth to reach the oil reservoir.This method of sinking a well into the ground is known as drilling.Answer:B. Drilling