What is the key difference between case studies and problem-based learning? A) Problem-based learning is always a fictional situation, case studies are always based on a real situation B) Selecting a case study to use comes after defining the outcome, and problem-based learning determines its own outcome C) There is no discernible difference between a case study and problem-based learning D) A case study includes the resolution and the results, problem-based learning requires students to develop a solution