Correct Option: B  [ Bone marrow ]
Remark:
Red Blood Corpuscles (RBCs), also known as erythrocytes, are formed in the bone marrow. Specifically, they are produced in the red bone marrow of large bones through a process called erythropoiesis. The hormone erythropoietin, secreted mainly by the kidneys, regulates this process. Mature RBCs are responsible for transporting oxygen from the lungs to body tissues using the pigment hemoglobin.
Other options (for context)
- Heart: Pumps blood but does not produce blood cells.
- Liver: In adults, it does not form RBCs (though it does in the fetal stage).
- Kidney: Produces erythropoietin hormone but not RBCs directly.