An organ within an organism accomplishes tasks. To engage in these tasks, an organ typically requires energy provided by other organisms.
B
interaction with other organ systems.
С
communication with other organisms.
D
segregation from other organ systems.

C) to ensure each new cell has an exact copy of the dna

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.