Ans.BConcussion: It is the most common type of traumatic brain injury.During head trauma, the head usually moves back and foh violently and there is a mismatch between the rapid deceleration and acceleration of the skull and the brain so that the brain hits repeatedly against the skull leading to concussion injury.Anterograde amnesia/Posttraumatic amnesia is a hallmark of concussion.In this type of amnesia, the events following the injury cannot be recalled.Headache, dizziness, nausea, vomiting like symptoms may present