Answer:
A. Add a semicolon and main clause it reminded me of a story I once read after ledge.
Step-by-step explanation:
New compound sentence.
"Long strands of ivy curled around the window ledge; it reminded me of a story I once read."
A compound statement is full on its own, but it becomes more significant when joined.
Even though each part of a compound sentence could stand on its own, putting them together gives the sentence more meaning.