Q. A 28-year-old man is brought to the ER because of confusion and impaired consciousness. He was riding his bike when he suddenly fell off, and he hit his head on a rock. He lost consciousness for 6 minutes then he became awake again and appeared fine, but 30 minutes later he was confused again so he was brought to the hospital. His temperature is 37.6 °C , HR is 90 beats/ minutes, BP is 165/90, and RR is 19 breaths/minutes. He is lethargic. On cognitive testing, he is oriented to place and person but not to time. The remainder of his neurological exam is unremarkable. A CT scan of his head is ordered and the results are shown below. Which of the following is the correct diagnosis?