Concept:Blood clotting factors are released by platelets, also known as thrombocytes, which are essential for haemostasis.
Explanation:When a blood vessel is injured, platelets adhere to the site, become activated, and aggregate to form a temporary plug.
During this process, platelets release clotting factors from their granules.
These factors include proteins such as fibrinogen (Factor I), prothrombin (Factor II), and Factor VIII, which work in a cascade to form a stable fibrin clot.
Platelets also secrete calcium ions (
Ca2+), which act as essential cofactors in the coagulation cascade.
In contrast, red blood cells (RBCs) are mainly responsible for oxygen transport, eosinophils are involved in allergic responses and parasite defence, and monocytes are part of the immune system as phagocytes.
None of these cell types release clotting factors; their functions are unrelated to coagulation.
Therefore, the only correct option is platelets (thrombocytes).
Answer:Platelets (Option C).