Abacterium would be considered?
a. unicellular
b. a cell
c. an organism
d. all the above

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.

looks like the answer is     c     to me!