Question

how is coal formed? marine organisms are accumulated in underwater sediment. sedimentary rocks are chemically transformed under high pressure. ancient plant remains are compressed and heated over millions of years. volcanic eruptions are deposited in layers of ash and rock over time.

Explanation:

To determine how coal is formed, we analyze each option:

• Marine organisms in sediment form oil/gas (not coal).
• Sedimentary rock transformation under pressure is not coal formation.
• Coal forms from ancient plant remains compressed/heated over millions of years (correct process).
• Volcanic eruptions deposit ash/rock (not coal formation).

Answer:

C. Ancient plant remains are compressed and heated over millions of years.