Which of the following are classified as white blood cells?

The classification of white blood cells, also known as leukocytes, includes specific types that play vital roles in the immune response and defense against infection. The correct answer includes basophils, eosinophils, lymphocytes, and monocytes—all of which are indeed types of white blood cells.

Basophils are involved in inflammatory reactions and can release histamine, which plays a role in allergic responses. Eosinophils are primarily responsible for combating parasitic infections and are also involved in allergic reactions. Lymphocytes are pivotal in the immune system, with T cells and B cells playing crucial roles in identifying and responding to pathogens. Monocytes can differentiate into macrophages and dendritic cells, contributing to both innate and adaptive immunity.

The other choices contain either components not classified as white blood cells or include red blood cells and platelets, which are part of the blood but serve different functions. Platelets are involved in blood clotting, and red blood cells are responsible for transporting oxygen throughout the body. Therefore, the only option that correctly lists only types of white blood cells is the one that includes basophils, eosinophils, lymphocytes, and monocytes.