<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A critical care fellow is interested in whether the auscultatory finding of pulmonary rales can accurately predict hypervolemic state. He conducts a study in 100 patients with volume overloaded state confirmed by a Swan Ganz catheter in his hospitals cardiac critical care unit. He also recruits 100 patients with euvolemic state confirmed by Swan Ganz catheter. He subsequently examines all patients in the unit for rales and finds that 80 patients in the hypervolemic group have rales in comparison to 50 patients in the euvolemic group. Which of the following is the positive predictive value of rales for the presence of hypervolemia?? A: 80100, B: 50100, C: 80130, D: 5070, E: 100200,  <response>: This is a question about calculating positive predictive value PPV. PPV is defined as the proportion of patients with a positive test result who actually have the disease. To calculate it, we need the number of true positives TP and false positives FP. True positives are patients who tested positive and have the disease. Here, 80 patients in the hypervolemic group had rales.False positives are patients who tested positive but dont have the disease. Here, 50 patients in the euvolemic group had rales. So PPV TP TP FP 80 80 50 80130.C: 80130 