challenge: What is Maria Oliva-Hemker's position at the Johns Hopkins University School of Medicine?
  
  A. Vice Dean for Faculty and Director of the Division of Pediatric Gastroenterology, Hepatology and Nutrition
  B. Dean of the School of Medicine
  C. Professor of Pediatric Surgery
  D. Vice Dean for Faculty and Director of the Division of Pediatric Cardiology
  Answer: 