Question

the most numerous cells of blood are
leukocytes (wbcs).
thrombocytes.
mast cells.
erythrocytes (rbcs)

Explanation:

Blood cells include erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). Erythrocytes are the most abundant, as their primary role of oxygen transport requires them to be present in very high numbers compared to the other cell types. Mast cells are not a primary blood cell type and are found in tissues, not circulating blood in large quantities.

Answer:

erythrocytes (RBCs)