In evolution, fossils are naturally preserved in

Step 1: Analyze the question The question asks where fossils are naturally preserved. Fossils are the remains or impressions of organisms that lived long ago, and they are key evidence for evolution.

Step 2: Explain the concept Fossils form when dead organisms are buried quickly by sediments such as mud, sand, or volcanic ash. Over millions of years, the sediments harden into sedimentary rock. Minerals gradually replace or fill the hard parts of the organism (bones, shells, teeth), or leave an imprint or mold of it. This is why palaeontologists dig into rock layers (strata) to find fossils. The deeper the layer, the older the fossil generally is.

Step 3: Evaluate the options

• A. Rocks: Correct. Sedimentary rocks are the main natural site of fossil preservation.
• B. Water: Water can carry sediments, but organisms do not stay preserved in water over geological time.
• C. Chemicals: Chemicals (minerals) help in the fossilization process, but fossils are not "preserved in" chemicals naturally.
• D. Trees: Trees can preserve insects in amber (hardened resin), but this is a special, rare case. Rocks are the general answer.

Step 4: Answer The correct option is A. rocks.

Tip: Remember the link: Fossils → Sedimentary rocks → Strata. If a WASSCE or JAMB question asks where fossils are found or preserved, think "rocks" first. Amber in tree resin is the exception, so only choose it if the question mentions insects or resin.