An old man is currently in the Intensive Care Unite with a severe head injury after an accident. He has orders for nothing by mouth and he is mechanically ventilated. He has a history of hypertension and atrial fibrillation. His blood pressure is 135/88 mm Hg, heart rate is 89 BPM. Which of the following risk factors put this patient at the highest risk for stress related mucosal damage? Explain in detail your answer and the other choices?

A. NPO and severe head injury

B. mechanical ventilation and hypertension

C. hypertension and atrial fibrillation

D. severe head injury and mechanical ventilation