Which of the following drugs serves a role in the reversal of anticoagulation?

Vitamin K plays a crucial role in the reversal of anticoagulation, particularly in patients who have been treated with warfarin. Warfarin functions as an anticoagulant by inhibiting the synthesis of vitamin K-dependent clotting factors, which include factors II, VII, IX, and X. When a patient experiences excessive bleeding or needs to reverse the effects of warfarin for surgery, vitamin K can restore the synthesis of these clotting factors. By administering vitamin K, the body can produce new clotting factors that are essential for normal coagulation, effectively reversing the anticoagulant effects of warfarin.

In contrast, while warfarin is an anticoagulant itself, it does not reverse anticoagulation. Clopidogrel is an antiplatelet medication that reduces the risk of blood clots but does not have any role in reversing anticoagulation. Streptokinase is a thrombolytic agent used to dissolve blood clots, and it also does not reverse the effects of anticoagulants. Therefore, vitamin K is the appropriate choice as it specifically aids in counteracting the anticoagulation caused by warfarin treatment.