Answer: poor soil
Explanation: dead plants, horse manure, and NPK are organic, whether they be organic organisms themselves, or created and considered organic molecules, soil, or dirt is inorganic.
Both a and b. Protists can be heterotrophic (organisms that get their nutrition from complex substances) or autotrophic (organisms that make their own nutritional substances).
This question isn't really finished, but bacterium are unicellular prokaryote.
I hope this helps?.. :S