What is the primary function of eosinophils?

Eosinophils primarily function to defend against parasitic infections. They play a crucial role in the immune response, particularly in combating larger parasites that can be difficult for other immune cells to manage, such as helminths (worms). Eosinophils achieve this through a variety of mechanisms, including the release of toxic granules and enzymes that can damage or kill the parasites. Additionally, eosinophils are involved in modulating allergic responses and asthma, often responding to allergens and contributing to inflammation. Their unique properties make them particularly effective at targeting and eliminating parasitic infections, which is why this answer is emphasized as the correct one.