Appendicitis (inflammation of the appendix) is potentially fatal; consequently, patients with symptoms strongly suggesting appendicitis almost always have their appendix removed.  The appropriate surgery is low-risk but performed unnecessarily in about 20 percent of all cases.  A newly developed internal scan for appendicitis is highly accurate, producing two misdiagnoses for every 98 correct diagnoses.  Clearly, using this test, doctors can largely avoid unnecessary removals of the appendix without, however, performing any fewer necessary ones than before, since ______.

A the patients who are correctly diagnosed with this test as not having appendicitis invariably have medical conditions that are much less serious than appendicitis
B the misdiagnoses produced by this test are always instances of attributing appendicitis to someone who does not, in fact, have it
C all of the patients who are diagnosed with this test as having appendicitis do, in fact, have appendicitis
D every patient who is diagnosed with this test as having appendicitis has more than one of the symptoms generally associated with appendicitis
E the only patients who are misdiagnosed using this test are patients who lack one or more of the symptoms that are generally associated with appendicitis
   Answer: B

答案是B，C为什么不对，想不通，请高人给看看

我没看懂以前的讨论,感觉并不好. 这题问的问题为什么有必要做的手术减少了.

B这句话理解的不是很清楚. 我的理解是:这些错误的诊断都是归于"诊断出那些来看病的

人是没得阑尾炎的".但这些人确实得了,因此就会有"必要的手术"减少了.

是根据答案来解释的.~!~

我觉得其实这题就是两个逻辑元素之间存在跳跃，需要把他们联系起来，unnecessary and misdiagnosis,

misdiagnosis can be those diagnosed as having A but, in fact, havent or those diagnosed as not having A but,actually, have. while unnecessary clearly means those havent but diagnosed as having. Therefore, here, choice B sovles the problem by effectively connecting these two elements.