Answer:
The correct answer will be option platelets.
Step-by-step explanation:
Blood plasma is the yellow part of the liquid part of the blood which constitute about 55% of the total volume of the blood. The blood plasma contains important proteins which are - Albumin (60%) , Globulin (35%) and Fibrinogen (4%) along with hormones, nutrients, amino acids and nitrogenous waste.
The centrifugation of the blood divides the blood into three parts:
1. The lowermost part: occupies about 45% of the total sample composed of RBC.
2. The middle layer: occupies only 1% of the total sample composed of WBC and platelets.
3. The uppermost layer: occupies about 55 % of the total sample composed of blood plasma.
Since the platelets are observed in the middle layer after centrifugation, therefore, the platelets is the correct option.