Final answer:
Platelets (c) carry the highest risk of febrile nonhemolytic transfusion reaction.
Step-by-step explanation:
The blood product that carries the highest risk of febrile nonhemolytic transfusion reaction is Platelets (c). Febrile nonhemolytic transfusion reactions are a common type of transfusion reaction that often occur due to patient antibodies reacting with the donor platelets, causing fever, chills, and other symptoms. These reactions are typically caused by antibodies against human leukocyte antigens (HLA) present on the donor platelets.