Final answer:
Red blood cells, containing hemoglobin, are responsible for picking up oxygen in the lungs and distributing it to all body cells.
Step-by-step explanation:
The component of the blood responsible for picking up oxygen in the lungs and carrying it to all the body cells is red blood cells or erythrocytes. Red blood cells are equipped with hemoglobin, a protein that binds to oxygen, facilitating the transportation of oxygen throughout the body. When blood reaches the lungs, oxygen crosses the lung tissue and enters the bloodstream, where it binds to hemoglobin in red blood cells. This oxygen-rich blood is then circulated to the body's cells where oxygen is released to support cellular functions.