Answer:
Hemopoiesis
Step-by-step explanation:
Blood is the main connective tissue and consists of plasma and formed elements. The formed elements of blood are erythrocytes, leukocytes and thrombocytes.
Hemopoiesis is the process of formation of red blood cells, white blood cells and platelets. The process of hemopoiesis in adults occur in the bone marrow. Hemocytoblast leads to the formation of all formed elements of the blood.
Thus, the correct answer is option (B).