Which of the following characteristics is true about an organism whose remains formed a good index fossil. a.) it must be unique orgsnism
b.) it must be an organism that lived all around the world
c.) it must be an organism that lived for a very short time period
d.) all of these characters are important fo an index fossil

d.) all of these characters are important fo an index fossil

Explanation:

Organisms have the characteristics to die and their remains form fossils. A fossil is a preserved remain of a previously living organism. Index fossils are fossils used to tell us more about a particular period. However, before the fossil remains of an organism can be used for this purpose, it must have specific characteristics including the following:

- It must be a unique/distinct species

- It must be geographically abundant

- It must live only a short period of time

Based on these above characteristics of a good index fossil, an organism whose remains must form a good index fossil must possess ALL THE MENTIONED CHARACTERISTICS MENTIONED IN THE OPTIONS.