Final answer:
The incorrect pairing is option C: acetylcholine decreases digestion, as acetylcholine actually increases digestion by stimulating the digestive processes.
Step-by-step explanation:
The question asks which of the following is an incorrect pairing concerning the effects of certain neurotransmitters and hormones:
- norepinephrine dilates the pupil
- epinephrine increases blood pressure
- acetylcholine decreases digestion
- norepinephrine increases heart rate
The incorrect pairing here is option C: acetylcholine decreases digestion. Acetylcholine actually increases digestion by stimulating the muscles of the gastrointestinal tract and increasing peristalsis and secretions that are necessary for the digestion of food. Therefore, the correct association for acetylcholine would be that it increases digestion, not decreases it.