Scientists determine that the rocks in the ash layer are 200 million years old. Several types of fossil organisms can be found below the ash layer but not above it.

What is the most reasonable conclusion from this information?

(Will give extra points)

The conclusion we can draw from this information is that just below the ash layer there are the necessary conditions for the formation of the fossils.

Explanation:

As you may already know, fossils are the remains of organisms that were trapped in deep layers of rocks, generating a record of the life of these organisms.

In relation to the question above, there is information that fossils can only be formed below a layer of ash and never above that layer. This information is correct. This is because below the gray layer there are all factors such as humidity, pressure and the presence of microorganisms, necessary for fossilization to occur. On top of the ash layer it would be impossible for fossilization to occur, because the remains of organisms would not be stored, but would be exposed to all the factors that would degrade these remains causing them to disappear, quickly, from nature.

a and b because with the other three, they simplify to something else.