Option (2) is the answer because, basophils secrete histamine, serotonin, heparin etc. and are involved in inflammatory response. Option (1) is not the answer because, basophils are granulocytes. Option (3) is not the answer because, neutrophils are the most abundant cells (60−65%) of the total WBCs whereas basophils are least (0.5−1%) abundant of all WBCs. Option (4) is not the answer because, monocytes have a kidney-shaped nucleus.