Your answer is (B.)
Fossils in newer layers if rock are generally estimated to be younger than fossils found in the deeper layers because it is closest to the surface. The soil and earth didn't have enough time to "bury" the remains of the dead animal ( Bury is used for a simpler term) underground. The farther down a fossil is the more likely it is older unless the animal tends to burrow. Seeing as the question is probably talking of older animals that is unlikely for an animal to burrow that far. So your answer is B.
I would say the 2nd one It helps growth and repair of cells of orgasms
But your school would probably say the 3rd one It helps remove toxins from the body to maintain homeostasis
Since IDK which two you would choose, I'll just list all of them: fish have developed a light, streamlined body to get through water quickly to evade predators with and swim with ease, owls have big eyes so their pupils can get enough light to see in the dark since they're nocturnal, their light bodies and special (Fluffy???) flight feathers let it fly with virtually no sound, allowing it to sneak up on prey, tortoises have a large, hard shell for protection from predators and provides a mobile home on their back! Bats may be practically blind but that doesn't stop them when using echolocation to detect prey and chase it no matter what moves they make or obstacles in the way, snowshoe hares have big feet to sit on top of the snow in the cold winters where they live, their fur also changes colors as the snow melts and the plants start coming back in the more warmer seasons, poison dart frogs, sorry, IDK, cacti have developed spines all over them as self defense, (from what IDK) and they can last a long time without water (I think, don't quote me on that ^^') hope this helps
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
