Final answer:
The buffy coat in a centrifuged blood sample consists of leukocytes (white blood cells) and platelets (thrombocytes), making option c (WBC and PLT) the correct answer.
Step-by-step explanation:
The buffy coat is a thin, pale layer found in a sample of centrifuged blood, which separates the red blood cells (erythrocytes) from the plasma. This coat consists of leukocytes (white blood cells) and platelets (thrombocytes). Therefore, the correct answer to the question "The buffy coat, within a plasma sample consists of which two components?" is "c. WBC and PLT" - white blood cells and platelets.