A conscious victim who has suffered a blow to the head has symptoms that indicate the possibility of concussion. If the patient feels no indication of neck or spine injury，recommended treatment would include（）.
- Aturning the victim's head to the side to keep his airway open
- Bpositioning the victim so the head is lower than the body
- Cgiving the victim water if he is thirsty，but no food
- Delevating the head and shoulders slightly with a pillow