question: Q:A 28-year-old man comes to his general practitioner for a regular checkup. He has had trouble breathing lately with coughing, shortness of breath, and wheezing. Problems first started when he went running (outside), but he is also observing the problems when taking a light walk or resting. As a child, he suffered from atopic dermatitis, just like his father and sister. He also has a history of hay fever. What is the most likely cause of his symptoms?? 
  {'A': 'Exercise', 'B': 'Chronic obstructive pulmonary disease', 'C': 'Type I hypersensitivity', 'D': 'Smoking', 'E': 'Type IV hypersensitivity'},