National Dental Examining Board of Canada (NDEB) Practice Exam

Warfarin is an anticoagulant medication, which means it helps prevent blood clots from forming. This is achieved by inhibiting the production of prothrombin, a necessary protein for blood clotting, in the liver. The other options are incorrect because they either promote blood clotting (A), are unrelated to blood clotting (B), or increase the number of red blood cells rather than inhibit blood clotting (C).