Which of the following statements about platelets is INCORRECT?

• A. The life span of platelets is between 30 and 60 days.
• B. Platelets are essential for the clotting process.
• C. Platelets contain serotonin, ADP, calcium, and PDGF.
• D. Platelets are fragments of a larger cell called a megakaryocyte.
• E. The formation of platelets is regulated by the hormone thrombopoietin.