Which of the following statements is correct?
fossils form only from the hard parts of extinct organisms.
fossils from rocks under other rocks are younger than the fossils found above them.
most fossils formed during a few catastrophic events.
fossils form in sedimentary rocks.

4. Fossils form in sedimentary rocks

Explanation:

A fossil expresses the traces or is the remains of prehistoric plant or animal that has died and its body part has been carefully been imprinted on to the surface of the rock that is sedentary as they have the characteristics of the mineral preserving qualities. There age , method of formation and evolutionary significance can be well established by the fossil remain in rocks that depict there occurrence throughout the carbon dating of the rocks. The process that leads to the formation of fossil is Personalization, casts and molds, recrystallization and Carbonization. Tracing a fossil consisting of digging out the track and burrows. Some fossil is found in deposits of resins which complete preserve the fossils from erosion process.

The answer to this question is  c. pharmaceutical accumulation  reclaimed water refers to the water that being used again after it already  used for agricultural purposes.this type of water often contains pharmaceutical accumulation because of the chemical fertilizer that is used for the plants is absorbed into the water.