Two days after a cesarean delivery for fetal distress, a 27-year-old woman has temperatures to 38.2°c (100.8°f). she had an 8-hour labor complicated by mild meconium-stained amniotic fluid. membranes ruptured 2 hours after admission. breath sounds are decreased at both lung bases. abdominal examination shows mild tenderness below the umbilicus and a well-healing incision. there is a moderate amount of lochia with no odor. examination of the lower extremities shows edema and no tenderness. her hemoglobin concentration is 10.8 g/dl, leukocyte count is 14,000/mm3, and platelet count is 189,000/mm3. a urine catheter specimen is negative. which of the following is the most likely diagnosis? atelectasis deep venous thrombosis endometritis episiotomy infection mastitis pneumoniapulmonary pelvic thrombophlebitisureteral obstructionurinary tract infection