Which of the following statements about head injury and concomitant hyponatremia are true? A. There are no primary alterations in cardiovascular signs. B. Signs of increased intracranial pressure may be masked by the hyponatremia. C. Oliguric renal failure is an unlikely complication. D. Rapid correction of the hyponatremia may prevent central pontine injury. E. This patient is best treated by restriction of water intake.