Final answer:
Noncatecholamines cause stimulation of CNS function.
Step-by-step explanation:
Norcatecholamines, which are indirect sympathomimetics, cause stimulation (choice A) of CNS function. These drugs mimic the activity of norepinephrine at synapses, leading to the activation of postganglionic fibers and the release of norepinephrine onto target organs. This stimulation of the sympathetic system can result in increased heart rate, pupil dilation, and other responses associated with sympathetic activation.