Although Japanese encephalitis often results in only mild symptoms, it

A) its symptoms are so severe and intractable that one in four cases

B) it is of such severity and intractability, one in four cases

C) so severe and intractable is it such that one in four cases

D) such is its severity and intractability, one of four cases

E) there is so much severity and intractability that one of four cases


Only A makes sense.

All other choices are either fragments or have modifying error

One in four cases are fatal? --- What a bad S-V agreement! All the five choices carry this fatal error.

Official Explanation

Creating a filter: no error jumps out in the sentence. "So that" is a valid idiom. We'll try to eliminate the other answer choices by finding objective defects.

Choice (B) introduces wordiness with no gain, and without a "that" in place of a comma, it creates a run-on sentence. In (C), "it is such that" is not a valid phrase and uses a pronoun that has no reference. Choice (D) has the same problems as (B). "Severity and intractability" would appear to describe the kind of severity, not the degree. (E) is not a run-on, but it describes severity and intractability as if they are easily quantifiable (with "so much") and generally present around us (with "there is").

The correct answer is (A).