THE CORRECT ANSWER IS (D). THE WORDS EXAMINATION, DIAGNOSING, AND...
21. The correct answer is (D). The words examination, diagnosing, and treatment are not
all grammatically parallel. One solution is to replace diagnosing with diagnosis. Also,
the first clause seems to refer nonsensically to patients because of this word’s proximity
to the clause. The solution is to reconstruct the sentence so that the clause is closer to
physicians than to patients. Choice (D) is the only alternative that corrects both
problems without creating any new ones.