Answer:
The automatic nervous system can be divided in to three main divisions namely; sympathetic nervous system, parasympathetic nervous system and enteric or intrinsic nervous system.
Intrinsic nervous system mainly governs the function of digestive system. it can either function independently or under the action of sympathetic and parasympathetic nervous system. Parasympathetic nervous system controls the enteric nervous system with the help of vagus nerve.
In addition, hunger is triggered or control by chemical messengers or hormones (such as ghrelin, insulin-like peptide 5, cholecystokinin etc.) in the body. These hormones act on hypothalamus which then regulates functioning of digestive system through nervous system.
Hence, the correct order would be:
Hormones signal that Monica is hungry.
Monica eats a snack while reading book.
Parasympathetic stimulation activates peristalsis for mechanical digestion.
Food is pushed through the stomach to the small intestine.
Enzymes in the small intestine begin chemical digestion.