A nursing instructor is teaching a group of nursing students about antihistamines. Which statement by a student indicates an understanding of the mechanism of action of the antihistamines?

C H1 antagonists can bind to H1 receptors, H2 receptors, and muscarinic receptors D First-generation antihistamines are more selective than second-generation antihistamines A Antihistamines block release of histamine from mast cells and basophils B Antihistamines block H1 receptors to prevent actions of histamine at these sites