Answer:
A. Adjust the platen
Step-by-step explanation:
Answering the question, since this is a dot-matrix printer, to properly hold the papers inserted in them, a dot-matrix printer makes use of the platen (which is basically a roller made of rubber). As it prints, it also uses this platen (roller) to advance the paper on which it is printing. Since one side of the paper being printed is dark and clear, it is possible that the paper is not being held evenly by the platen so adjusting the platen is a quick fix to correcting the issue.
By the way, dot matrix printers are great printers that print at relatively high speed and they make copies of their prints look exactly like the original prints.
Hope this helps!