6 man IS brought to the emergency department 20 minutes after he lost consciousness during preseason football practice. The outside temperature is 100T Hs coach reports that the patent had a concusstcn 1 year ago. On arrival, the patient is unconscious. He appears muscular His temperature is 40 60C (1050 F), pjse 130Trun and regular respirators are 28!mn, and blood pressure gs 80/60 mm Hg The skin is dry The pupils are equal, round, and reactive to light The remander of the exarnnatlon no abnormalities Which of the following IS the most appropriate next step In diagnosis? C A) blood culture C 8) CTscan Of the head C C) Echocadaøraphy C D) Unne toxicology screentng E) No addtonal dlagnostjc studies are tndca