You are answering a USMLE-style medical question. Question: A 26-year-old man presents to his physician with a history of diarrhea and vomiting for the past 24 hours. On physical examination, his temperature is 36.9ºC (98.4ºF), pulse rate is 110/min, blood pressure is 102/74 mm Hg, and respiratory rate is 16/min. A resident working under the physician plots a Darrow-Yannet diagram for the patient. The diagram is shown in the picture where the green dotted line represents the new fluid status. Which of the following is most likely to show increased secretion in this patient? Options: A) B-type natriuretic peptide B) Bradykinin C) Renin D) Vasoactive intestinal peptide Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.