The correct answer is option d, that is, neurotransmitters.
A neurotransmitter refers to a chemical component, which is discharged at the terminal of a nerve fiber by the introduction of a nerve impulse, and by diffusing across the junction or synapse. It helps in the transfer of the impulse to another muscle fiber, nerve fiber, or some other composition. Acetylcholine is a kind of neurotransmitter, that is, used by neurons in the CNS and the PNS in the control of activities ranging from heart rate and muscle contraction to digestion and memory.
Some advances is that organelles, cells, and the difference between the cells of a plant and a cell of an animal. This was an advance because not only did we discover new things but we learned how or body functions with them and how they work. Hopefully you got what you were looking for. :)
Answer:
they just help us break down the food and then procces the food to the other organs
Explanation:
