I think it's mitosis or meiosis
It is b or the second answer choice shown
Bone marrow plays an important role in our circulatory system because Bone marrow contains hematopoietic stem cells which is the major producer of red blood cells or erythrocytes,white blood cells also know as leukocytes and also platelets( thrombocytes) which is the major components of our blood,the only liquid that is very essential in our circulatory system.
Answer:
having traits that help a single organism survive
