question: Q:A 35-year-old female presents to her primary care physician because of chronic fatigue that has stopped her from gardening and walking with her friends. Upon further questioning, she elaborates that she feels fine after waking up but gradually becomes more tired and weak as the day progresses. This appears to be particularly problematic when she is engaged in physical activity or when eating. Review of systems elicits that she occasionally experiences double vision after spending a prolonged period looking at a computer screen. Testing confirms the diagnosis and the patient is prescribed a long-acting medication to alleviate her symptoms. The products of the enzyme that is inhibited by the prescribed drug are transported by a protein that is sensitive to which of the following chemicals?? 
  {'A': 'Botulinum', 'B': 'Guanethidine', 'C': 'Hemicholinium', 'D': 'Reserpine', 'E': 'Vesamicol'},