The correct answer is option D, that is, whole blood with an anticoagulant added.
The PCV or the packed cell volume determines the proportion of red blood cells present in the whole blood. It is one of the various tests, which may be used to diagnose or monitor a condition known as anemia. The test may also be used to diagnose or monitor a rare kind of blood cancer called polycythemia.
The PCV can be determined by centrifuging heparinized blood in a capillary tube at 10000 RPM for 5 minutes. This distinguishes the blood into layers. The volume of the packed RBCs divided by the total volume of the blood sample provides the PCV.