55. The following statements about neurologic form of Wilson disease are correct, except？ (A)Wilson disease is an autosomal recessive inborn error of copper transport。 (B)The neurologic manifestations usually appear before age of 10 years。 (C)The initial symptom is progressive dystonia and followed by tremors of extremities。 (D)Kayser-Fleischer rings are present in 95% of patients with neurologic symptoms。 (E) The serum “free” copper level may be elevated and urinary copper excretion is increased。