Answer:
An index fossil is a fossil used to determine the age of the sediments in which it is found. When quickly approximating the age of new finds, an archaeologist looks at the rocks in which it is buried, as those sediments would have been on the surface at the time of the death of the pre-historic creature.
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Your answer is (B.)
Fossils in newer layers if rock are generally estimated to be younger than fossils found in the deeper layers because it is closest to the surface. The soil and earth didn't have enough time to "bury" the remains of the dead animal ( Bury is used for a simpler term) underground. The farther down a fossil is the more likely it is older unless the animal tends to burrow. Seeing as the question is probably talking of older animals that is unlikely for an animal to burrow that far. So your answer is B.
In my opinion the best sounding answer is C I hope this helpes<span />
Answer:
Substance B is a group of hydroxide ions.
Explanation:
First of all, it needs a deposit of carbon. Then, mass amounts of pressure and heat will be applied to the deposit. Over time, the carbon turns into a crystal which is either burst out of a volcano or remains under the ground.