Final answer:
The correct answer is C) Decrease of blood pressure, because the parasympathetic nervous system's main actions include slowing down the heart rate and reducing blood pressure to conserve energy and restore the body's functions after a period of high-energy demand.
Step-by-step explanation:
The effect of the parasympathetic nervous system is generally to conserve and restore energy by slowing down the body's high-energy functions. Referring to the options provided:
- A) Increase in blood pressure: Increased blood pressure is a result of sympathetic nervous system activity, not parasympathetic.
- B) Dilation of pupil: The dilation of the pupil is also related to the sympathetic nervous system, as norepinephrine dilates the pupil.
- C) Decrease of blood pressure: This is an effect of the parasympathetic nervous system, which slows down the heart rate and lowers blood pressure.
- D) Secretion of digestive juices: The secretion of digestive juices is stimulated by the parasympathetic nervous system, facilitating digestion.
Therefore, the correct answer is C) Decrease of blood pressure, as the parasympathetic nervous system functions to slow the heart rate and lower blood pressure, among other things.