The diagram below shows an undisturbed rock. A rock sample is shown with four layers marked A, B, C, D from top to bottom. Which layer is likely to have the remains of an organism least similar to the organism's present-day form? Layer A Layer B Layer C Layer D

Layer D

Explanation:

The rock layer with remains of organisms least similar to present day form can be found in Layer D.

Since layer D is the oldest layer, it will contain the oldest fossil in the undisturbed sequence.

This is because of the principle of fossils and fauna succession.

The principle states that "fossils and fauna succeed on another in a definite order".

Option D which denotes layer D is the right choice.  

LAYER D

Explanation:

because the youngest layer is in the top, and the oldest layers are on the bottom.