Fossils of organisms that are different than today's organisms and are found in deeper rock layers indicates that A.
evolution has occurred
B.
organisms must have changed over time
C.
evolution occurred faster in the past
D.
Both A and B

D
Explanation:

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.