Which of the Following Is an Essential Characteristic of an Index

Multiple Choice

Which of the following is an essential characteristic of an index fossil?

A) The fossils are exceptionally abundant and well preserved.
B) The fossils occur in deep- water marine sediments, but the organism actually lived in the sunlit, surface layer of the ocean.
C) The organism only lived for a short period of geologic time.
D) The organism lived only in specific environments such as beaches or estuaries.