During which hemostatic phase does a 'scab' start to form?

The formation of a 'scab' occurs during the coagulation phase of hemostasis. This is the stage where blood begins to solidify in response to injury. When a blood vessel is damaged, platelets quickly adhere to the site and initiate temporary closure of the wound; this is part of the platelet phase. However, it is during the coagulation phase that clotting factors, which are proteins in the blood, become activated, leading to the transformation of fibrinogen into fibrin. Fibrin strands weave through the platelet plug and help stabilize it, ultimately forming a more durable clot. This clot then dries out and hardens, resulting in a scab, which protects the underlying tissue as it heals. Thus, the correct answer directly reflects this crucial process in hemostasis, as it relates to the formation of a scab.