As you move up an energy pyramid, all of the following decreases except for Select one:
a. the biomass for the trophic level
b. the energy at each trophic level
c. the number of organisms in each trophic level
d. the average percentage of energy lost as heat

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.