Answer:
The answer is D.
Step-by-step explanation:
We can easily knock out answer choice A, as fossils only take around 10,000 years to form completely. Not just for the organisms that lived 3 million years ago. Answer B as well, since theres been fossils for about just every animal out there. Answer C, we have seen the tiniest of organisms turn into fossils before, so this is outright wrong. Answer D, is correct. Why? Because fossils need the PERFECT conditions to be properly made. We´ve all seen a dead cat on the road or two. Everytime we visit, we notice how slowly more and more deterioated the body gets. Until theres nothing but maybe the skull and some other few spare bones left. Which those bones, soon turn into fertilizer for the ground / dirt beneath it.