challenge: What is Average Length of Stay (ALOS) typically calculated by?
  
  A. Adding the number of patient admissions and the number of inpatient days
  B. Multiplying the number of patient admissions by the number of days in the year
  C. Dividing the sum of inpatient days by the number of hospital beds
  D. Dividing the sum of inpatient days by the number of patients admissions with the same diagnosis-related group classification
  Answer: 