Erythropoiesis in adults starts in
Red bone marrow
Erythropoiesis
Erythrocytes are red coloured enucleated cells present in the blood. The process of formation of erythrocytes is termed as erythropoiesis. Erythrocytes are formed from haematopoietic stem cells present in red bone marrow. These cells differentiate to form red blood cells or erythrocytes.
Hence, the site for erythropoiesis is red bone marrow.
Final answer
(B) Red bone marrow