D) pro-time
A pro-time measures how long it takes for a clot to form. An erythrocyte
sedimentation rate determines the rate at which mature red blood cells settle out of the blood
after the addition of an anticoagulant. A culture and sensitivity test checks for bacteria and, if
present, which antibiotics will work on it. A hematocrit measures the volume of red blood cells
within the total volume of blood.