Answer:
the awnser should be A both present detailed information about storytelling traditions in several countries.
Yes. The sentence with correct parallel structure would be as follows. The doctor known only that her patient would improve, but also knew that her patient would [can't understand the sentence after that, but nevertheless it is still faulty].
The correct answer is parallel plot structure.
When it comes to parallel plot structure, it means that there are several characters whose stories we can see within a particular text. First we see what's going on with one character, then another one, etc. and at one point, they are going to meet, and there will be only one story from that point onward.
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