Final answer:
Amphetamine and ephedrine are sympathomimetic drugs that increase norepinephrine release, thus option b) Increase NE release is the correct answer to what these substances do.
Step-by-step explanation:
Amphetamine and ephedrine are sympathomimetic drugs that affect the sympathetic nervous system. These drugs work by increasing the production and release of norepinephrine (NE) at the synapses between sympathetic postganglionic fibers and their targets, or they may block the removal or reuptake of norepinephrine from the synapse. Consequently, the correct answer to the question is b) Increase NE release. Amphetamines and ephedrine do not inhibit monoamine oxidase, block alpha receptors, or enhance cholinergic transmission which refers to the activity of the neurotransmitter acetylcholine.