A child presents with a history of having had an upper respiratory tract infection 2 weeks ago; complains of symmetrical lower extremity weakness, back pain, and muscle tenderness; and has absent deep tendon reflexes in the lower extremities. Which of the following is true regarding this condition? 1. The disease process is probably bacterial. 2. The recent upper respiratory infection is not important information. 3. This may be an acute inflammatory demyelinating neuropathy. 4. CN involvement is rare.