Answer:
My BEST guess is A-Fact by fact.
Explanation:
The text talks about what mucus is, and what it is known for.
B-Problem and solution, could not be the answer because there, did not state a problem, nor solution.
C-Cause and effect couldn't be an answer because the text did not state any causes of mucus and the effect upon anything.
D-Chronological order, could 'possibly' be the answer, but in chronological order, there would be step-by-step issues, dates of where, why, and how it, mucus, appeared.
A-Fact by fact, gives information and facts about what mucus is and where it came from and gives you relevant input.
So the best guess that makes more sense is A!
I hoped this makes sense and helped you out some :)
