Which of the following white blood cells is primarily responsible for allergic reactions?

Basophils are primarily responsible for allergic reactions due to their role in the immune response and their ability to release histamine, a key chemical involved in allergic reactions. When an allergen is encountered, basophils release histamine and other substances that contribute to the symptoms of an allergy, such as inflammation, itching, and increased mucus production.

These cells not only play a critical role in the immediate hypersensitivity reactions associated with allergies but also in the body's defense against parasites. It's important to note that while eosinophils also contribute to allergic responses and are involved in combating parasitic infections, basophils are specifically noted for their function in initiating and propagating the allergic response directly through the release of their mediators.

Lymphocytes are more associated with the adaptive immune response and are not primarily responsible for immediate allergic reactions. Neutrophils, on the other hand, are primarily involved in fighting bacterial infections and do not directly participate in the processes that characterize allergic responses.