Respuesta :
The answer is c, because we use it as an "index" to tell when the animal lived, so if it's unique to that time level in the ground we know it lived that long ago.
The characteristic of a good index fossil is the organism lived only during a short part of Earth's history.
What is index fossils?
Index fossils are fossils that are used to identify and describe geologic periods.
Index fossils have a narrow vertical range, a large geographic distribution, and quick evolutionary tendencies.
These fossils are of the animals who lived for a short period of time.
Thus, the correct option is C. The organism lived only during a short part of Earth's.
Learn more about fossil, here:
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