Answer:
An index fossil should be found in many parts of the world.
Explanation:
A is not correct because if fossils are found in one area than they will not be able to give a general picture of the world in a particular period.
B is not correct because if fossils are found in only two locations they will be able to give information for only those two places, not the rest of the world.
C is not correct because this is simply not possible, not just for the number of fossils required, but also because the majority of the rock types don't provide conditions for fossilization.
D is correct because by being found in numerous places across the world, the index fossils can give a general picture of the biodiversity, but also the climate, and living conditions in a particular time frame.
