Identify a Difference Between Direct-Acting and Indirect-Acting Cholinergic Drugs

Identify a difference between direct-acting and indirect-acting cholinergic drugs.

A) Indirect-acting drugs bind to muscarinic receptors, whereas direct-acting drugs do not bind to any receptors.
B) Direct-acting drugs inhibit the activity of the enzyme acetylcholinesterase, whereas indirect-acting drugs enhance the activity of acetylcholinesterase.
C) Indirect-acting drugs increase cholinergic activity at all muscarinic and nicotinic receptors sites, whereas direct-acting drugs only increase cholinergic activity at the muscarinic receptor sites.
D) Direct-acting drugs lead to an increase in the concentration of acetylcholine in the synaptic cleft of all cholinergic nerve endings, whereas indirect-acting drugs do not affect the concentration of acetylcholine in the synaptic cleft of cholinergic nerve endings.