"Natural ecosystems provide an array of basic processes that affect and support humans."

Which statement does not support this quotation?

a
Bacterial decay helps recycle matter.
b
Trees add to the amount of atmospheric oxygen.
c
Lichens and mosses living on rocks help to break the rocks down, forming soil.
d
Treated sewage is less damaging to the environment than untreated sewage.

d

Treated sewage being less damaging to the environment than untreated sewage does not directly relate to natural ecosystems providing basic processes that affect and support humans.