question: Q:A 29-year-old woman comes to the physician because of poor balance and recurrent falls for the past month. She has also had blurry vision in her right eye for the past 2 weeks. She reports worsening of her symptoms after taking warm baths. Physical examination shows generalized hyperreflexia and an intention tremor. Romberg sign is positive. Visual acuity is 20/50 in the left eye and 20/100 in the right eye, and she is unable to distinguish red from green colors. The cells primarily affected by this patient's condition are most likely derived from which of the following embryologic structures?? 
  {'A': 'Mesoderm', 'B': 'Endoderm', 'C': 'Neuroectoderm', 'D': 'Neural crest', 'E': 'Notochord'},