Granulocytes make up 65% of the white blood cells and they have thin granules. They are divided into neutrophils, eosinophils, mast cells, and basophils. The correct answer to this question is neutrophils. This is because it covers approximately 40 % – 50% of the total granulocyte count which is the most out of all the others. They are the most important part of the immune system and it plays different roles in different species. This is why, out of all the options we have; neutrophil granulocytes are the correct option and this is the most abundant granulocyte in the human blood.