Question

index fossil
location 1
north america
location 2
south america
location 3
africa
location 4
europe
they are all found in europe.
they all likely existed during the same time period.
they prove that the earth was once one supercontinent
they are older than the fossils above them

Explanation:

• The first option is incorrect because the fossils are found in multiple locations (North America, South America, Africa, Europe), not just Europe.
• The second option is correct. Index fossils are used to date the rock layers they are in. If the same fossils (like A, B, C in different locations) are present, they likely existed during the same time period.
• The third option is incorrect. While similar fossils in different continents can support the idea of continental drift (which implies a supercontinent in the past), the presence of these fossils alone does not "prove" the Earth was once one supercontinent. There is more geological evidence (like rock formations, mountain ranges) needed for that claim.
• The fourth option is correct. In undisturbed sedimentary rock layers, lower - lying fossils are older than those above them. This is based on the principle of superposition.

Answer:

They all likely existed during the same time period; They are older than the fossils above them.