A client with allergies has been prescribed an antihistamine. Which response by the client demonstrates understanding of the action of antihistamine drugs?

"Antihistamines act by increasing dilation of blood vessels.”.

"Antihistamines act by blocking the release of hormones.”.

"Antihistamines act by increasing the production of acetylcholine.”.

"Antihistamines act by blocking histamine receptors in tissues.”. . . .