Although the ratio of physicians to total population is about the same in the LACENAME>UnitedLACENAME> LACETYPE>StateLACETYPE> and Canada, the LACE>United StatesLACE> has 33 percent more surgeons per capita. Clearly, this is the reason people in the United States undergo 40 percent more operations per capita than do Canadians.

The explanation given above rests on an assumption that

(A)patients in the LACE>United StatesLACE> do not have a greater need for surgery than do patients in LACE>CanadaLACE>.

(B)the population of the United States is not larger than that of Canada.

(C)United States patients sometimes travel to Canada for certain kinds of surgery.

(D)general practitioners in the United States do not as a rule examine a patient who is a candidate for surgery before sending the patient to a surgeon.

(E)there are no unnecessary surgical operations performed in Canada.

I choose A but am not confident. Please help. Thanks

E
填gap:33% more surgeon与40%more operation之间的gap

只有当加拿大人不做无意义的手术时，才会出现美国人因内科医生多做

手术

a的错误，我认识是need。因为need并不意味事实上的做手术，有need不见的会

undergo

不知道到nn怎么认为。。。