The correct answer is: a) Sedimentation and decomposition.
Petroleum is formed from the remains of ancient organisms that lived in the oceans millions of years ago. These organisms died and sank to the bottom of the ocean, where they were buried under layers of sediment. Over time, the heat and pressure from the overlying sediment caused the organic matter to decompose and form hydrocarbons. These hydrocarbons were then trapped in porous rocks, where they have remained until they were discovered and extracted by humans.
Volcanic activity does not play a role in the formation of petroleum. Metamorphic transformation is the process by which rocks are changed from one type to another by heat and pressure. Glacial deposition is the process by which glaciers deposit sediment. None of these processes are involved in the formation of petroleum.
Sedimentation is the process by which material is transported and deposited by water, wind, or ice. Decomposition is the process by which organic matter breaks down into simpler substances. These two processes are essential for the formation of petroleum.