The correct order is: D: "Prioritising drinking water source sustainability is one of the essential priorities identified." A: "Unfortunately, it is narrowly defined as protecting water sources in the immediate vicinity." B: "The larger dimensions are often left out." C: "Source sustainability also needs to be made a convergence priority." This sequence (DABC) starts by introducing the main priority (drinking water source sustainability), then highlights a limitation in its definition, explains what's missing, and finally calls for a broader approach. So, the answer is Option A: DABC.