You are answering a USMLE-style medical question. Question: A 52-year-old man is brought to the emergency department for recurrent vomiting that began 5 hours ago. He describes the vomitus as bloody and containing black specks. He drinks 10–12 beers daily and has not seen a physician in 15 years. He appears pale. His temperature is 36.7°C (98.1°F), pulse is 122/min, and blood pressure is 85/59 mm Hg. Physical examination shows decreased radial pulses, delayed capillary refill, multiple spider angiomata, and a distended abdomen. He is oriented to person but not to place or time. Which of the following is most likely decreased in this patient in response to his current condition compared to a healthy adult? Options: A) Systemic vascular resistance B) Fractional tissue oxygen extraction C) Carotid baroreceptor firing activity D) Cardiac inotropy Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.