What is the primary function of an anticoagulant?

Anticoagulants primarily function to delay or prevent blood clotting, making them essential in various medical situations where there's a risk of thrombosis or embolism. By inhibiting specific factors in the coagulation cascade, anticoagulants maintain blood fluidity, which is crucial for preventing blockages in blood vessels that can lead to serious conditions such as heart attacks or strokes.

In contrast, enhancing the immune response relates to immunological agents, not anticoagulants. Promoting blood clot formation contradicts the purpose of anticoagulants, as they are designed to prevent clotting rather than facilitate it. Facilitating blood transfusion is unrelated to the mechanism of action of anticoagulants, which do not play a role in the transfusion process but focus on the regulation of clotting. Thus, the primary function of an anticoagulant is indeed to delay or prevent blood clotting.