Final answer:
Diphenhydramine (Benadryl) is the medication that blocks the release of histamines, functioning as an antihistamine, which is used to treat allergy symptoms.
Step-by-step explanation:
The medication that blocks the release of histamines is Diphenhydramine (Benadryl). Diphenhydramine is classified as an antihistamine, which works by preventing histamines from having an effect on the body. Antihistamines like diphenhydramine bind to histamine H₁ receptors in various parts of the body such as mast cells and smooth muscle, thereby blocking the actions of histamine and the symptoms it can cause, like itching, runny nose, and sneezing. Other medications listed, such as Albuterol and Epinephrine, do not primarily function as antihistamines; rather, they are used to treat conditions like asthma and anaphylactic shock, respectively. Acetaminophen is a pain reliever and fever reducer but does not have antihistaminic properties.