I think it’s A
Hopefully this helps!!
<span>bones and footprints preserved in stone are examples of fossils. Fossils hardened animal remains such as shells, bones, and teeth.</span> That is the best i can come up with. Hope it helps any.
Answer:
I am guessing The second Cause only petroleum stay in the top of water
There are two events,
A: the selection belongs to the specific species, or
A' : the selection does not belong to the specific species.