Sometimes the immune system overreacts from exposure to a normally harmless thing like cat hair. Subsequent exposure to this allergen elicits a massive inflammatory response. Because the chemical histamine is the cause of this inflammation, what cell type is most likely behind the problem?

the mast cells and basophils.

Explanation: mast cells are the histamine secreting cells of the body. Histamine act to as a defense system by triggering a reaction to combat the effect of the allergy, thereby leading to inflammation, sneezing and other allergy symptoms Basophils, a type of white blood cell also secrete histamine and are also responsible for some inflamatory reactions as a way of immune response.

thermophiles, notice the prefix thermo.

i think the answer would be d