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 morecost-effective than others. One theory is that Certification Level is an important factor in measuring thecost-effectiveness of physicians. To investigatethis, the HMO obtained independent random samples of 28 physicians from each of the three certificationlevels--Board certified(C); Uncertified, board eligible(E); andUncertified, board ineligible(I)--and recorded the totalper-member, per-month charges for each(a total of 84 physicians). In order to compare the mean charges for the threegroups, the data will be subjected to an analysis of variance. Write the alternative hypothesis tested by the ANOVA.

A.

The three certification levels do not have the same mean charge.

B.

One certification group has the same mean charge as a different certification group.

C.

The 84 physicians all have the same charge.

D.

The three certification levels do not all have the same mean charge.