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.
Tadpoles use GILLS to obtain oxygen
A,B,D are correct so C , is the one that will change the cell theory
Individuals who have some combination of male and female genitalia, gonads and chromosomes are called hermaphrodites or inter-sexuals.