Answer: "c. "The onset of warfarin is delayed."
Step-by-step explanation:
Warfin is a drug which has a delayed action on the body. It is not useful for blood coagulation or platelet aggregation. Thus it cannot be used for the purpose of treating thromboses or in emergency treatment.
Heparin has a short half life and it exhibit side effects. Thrombosis is the process of formation of blood clots inside the blood vessels. This prevents the normal flow of blood in the circulatory system. Heparin is an anticoagulant it helps in thinning of blood. Hence, it is useful in the given condition.