Which Attribute Is Most Correctly Associated with Substances Known as Neuromodulators

Which attribute is most correctly associated with substances known as neuromodulators?

A) produced in the brain but exert effects on other organs
B) affect the activity of only one or a few neurons
C) inhibit the synthesis or degradation of neurotransmitters
D) influence the activity of a large number of neurons
E) modulate the activity of non-neuronal cells in the central nervous system