A nurse is providing care to a client who has peritonitis. Which of the following conditions is the highest priority for the nurse to monitor?

A. Respiratory failure may occur in severe illness, but it is not the most direct or immediate threat in peritonitis. B. Sepsis is the most critical complication of peritonitis, as the infection can rapidly enter the bloodstream, leading to systemic inflammatory response and organ failure. C. Heart attack is not a typical or direct complication of peritonitis. D. Diabetes is a chronic condition and a risk factor but is not an acute complication of peritonitis itself.