Upon arrival to the emergency room, the mother of a client involved in a motor vehicle accident becomes upset when she learns her son is unconscious and unstable. The mother begins to yell at the emergency room staff in unintelligible words, and she is trembling. She becomes short of breath and yells she can't breathe. What is the mother likely experiencing?A: fearB: a coping mechanismC: a psychosomatic disorderD: anxiety