A nurse is assessing a client who is taking warfarin. Which of the following findings should the nurse identify as the priority to report to the provider?

A. Fever can be a sign of infection or other conditions but is not directly related to warfarin therapy. It should be monitored but is not the priority in this context. B. Melena, or black tarry stools, indicates gastrointestinal bleeding, which is a serious and potentially life-threatening complication of warfarin therapy. This finding should be reported to the provider immediately. C. Abdominal cramping can be caused by various conditions and is not specifically related to warfarin therapy. It should be assessed but is not the priority. D. Hair loss can occur with long-term use of warfarin but is not an immediate concern. It is a less critical side effect compared to bleeding complications.