Question

The dead aquatic organisms that were buried under the sand and clay of the sea bed, were converted to petroleum owing to:
A.absence of air
B.high temperature
C.high pressure
D.all of the above

Answer 1

The dead aquatic plants, algae and different organisms that were buried under the sand and clay of the sea bed, are converted to petroleum owing to some necessary conditions like the absence of air, high temperature, and high pressure.

Complete step by step answer:
Petroleum is a naturally forming, black liquid found in geological formations below the Earth's surface. It is a fossil fuel and also a non-renewable source of energy. Fossil fuels are formed by the dead remains of living organisms which get buried under the earth, a million of years ago.
The conditions that would eventually create petroleum formed millions of years ago, when sea organisms drifted in oceans and shallow seas. These organisms floated to the seafloor at the end of their life cycle. Later, they were buried and crushed under millions of tons of sediment and even more layers of plant debris.
Some necessary conditions for this are:
High temperature: The organic material is compressed between Earth’s mantle, with very high temperatures, and millions of tons of rock and sediment above.
Absence of air: Oxygen is completely absent in these conditions, and the organic matter begins to transform into a waxy substance named kerogen.
High pressure: With more heat, time, and pressure, the kerogen undergoes a process called catagenesis, and transforms into hydrocarbons. In this way, Petroleum is formed.

Thus, the correct answer is option D.

Note: As the organisms in the sea die, their bodies settle at the bottom of the sea. These bodies get covered with layers of sand and clay. After many years, in the absence of air, and under high temperature and pressure the dead bodies are converted into petroleum and other natural gases.