Answer:
the brain stem
Explanation:
the structures of our brain stem, in conjunction with our spinal cord (not a part of our brain) is responsible for involuntary action. Not sure if it generate signals, but hey it's better than no answer.
Both answers C and D are correct, however, answer D makes more sense.
D,E,G is the correct answer
The correct answer would be D) decomposers. Decomposers do just what they're named for. Decompose things. They break down dead plant and animal material, gaining nutrients from it, while releasing CO2 into the atmosphere.