The correct answer is Option B : B and C only.

Statement A is incorrect. Basophils are actually the least abundant cells of the total white blood cells (WBCs), not the most abundant.

Statement B is correct. Basophils do secrete histamine, serotonin, and heparin. Histamine and serotonin are involved in inflammatory response, while heparin is an anticoagulant.

Statement C is also correct. Basophils are involved in the inflammatory response. They release chemicals such as histamine and serotonin that dilate blood vessels and attract other white blood cells to the site of inflammation.

Statement D is incorrect. Basophils do not have a kidney-shaped nucleus. That description is more appropriate for monocytes, another type of white blood cell.

Statement E is incorrect. Basophils are not agranulocytes. They are granulocytes, a category of white blood cells characterized by the presence of granules in their cytoplasm. Agranulocytes, which lack visible cytoplasmic granules, include lymphocytes and monocytes.