A. Blood pressure increases: Parasympathetic activity tends to reduce vascular tone and cardiac output, so blood pressure usually decreases rather than rises. B. Bronchioles dilate: The parasympathetic system causes bronchoconstriction, while bronchodilation is a sympathetic response. C. Pupils dilate: Pupil dilation (mydriasis) is controlled by the sympathetic system; the parasympathetic system produces constriction (miosis). D. Heart rate decreases: Parasympathetic stimulation via the vagus nerve slows SA node firing, leading to a reduced heart rate.