Final answer:
Reticulocytes are immature red blood cells that ultimately mature into erythrocytes that function primarily to transport oxygen throughout the body.
Step-by-step explanation:
Reticulocytes are immature red blood cells (RBCs), which are released into the bloodstream from the bone marrow. The primary function of reticulocytes is to mature into erythrocytes, or mature red blood cells, which transport oxygen to the body's cells and tissues. These cells are equipped with hemoglobin, a protein that binds oxygen and facilitates its delivery throughout the body. Although they may initially contain some remnants of organelles, reticulocytes quickly lose these as they transform into erythrocytes, which lack nuclei and other organelles. This design allows erythrocytes to carry maximum amounts of oxygen since their internal space is predominantly occupied by hemoglobin. Hence, the correct answer to the student's question is that the function of reticulocytes is to transport oxygen (Option 1).