Which statement best describes how crude oil and natural gas are formed?

The formation of crude oil and natural gas primarily involves the remains of tiny organisms, particularly microscopic plants (like phytoplankton) and animals (such as zooplankton) that lived in ancient seas. As these organisms died, they accumulated on the seabed and were buried under layers of sediment. Over millions of years, the heat and pressure from the overlying sediments transformed the organic material into hydrocarbons, which constitute crude oil and natural gas.

This process is a complex interplay of biological, geological, and chemical processes, and it is essential to understand that the specific conditions required for the formation of these fossil fuels are typically found in marine environments, rather than in deserts or forests. Therefore, the description correctly identifies the origin of crude oil and natural gas as being from the remains of tiny marine organisms buried under sediments, which is the foundational basis for their formation.