Final answer:
An erythrocyte, or red blood cell, is the mature cell that possesses no nucleus, mitochondria, or ribosomes; it uses hemoglobin to transport oxygen.
Step-by-step explanation:
The mature cell that has no nucleus, no mitochondria, and no ribosomes is an erythrocyte (A). Erythrocytes, also known as red blood cells, extrude their nucleus during development to make room for more hemoglobin, which is essential for oxygen transport. Since they also do not contain mitochondria or ribosomes, they rely on glycolysis for energy, which takes place in the cytoplasm. Platelets, also called thrombocytes (C and D), have some organelles but are actually fragments of cytoplasm derived from megakaryocytes and are not considered whole cells. Leukocytes and neutrophils (B and E) are types of white blood cells that both contain a nucleus and organelles.