A Certain HMO Is Attempting to Show the Benefits of Managed

A certain HMO is attempting to show the benefits of managed care to an insurance company. The HMO believes that certain types of doctors are more cost-effective than others. One theory is that
Certification level is an important factor in measuring the cost-effectiveness of physicians. To
Investigate this, the HMO obtained independent random samples of 27 physicians from each of the
Three certification levels-Board certified (C) ; Uncertified, board eligible (E) ; and Uncertified, board
Ineligible (I) - and recorded the total per member per month charges for each (a total of 81
Physicians) . How many factors are present in this study?

A) 81
B) 3
C) 1
D) 27