Review the item:
In preparation for the quiz, La'Mia studied comma splices and fused
sentences until she thought her brain would burst,
finally, she put away her notes, convinced that she would remember
the rules even on her death bed.
For a sentence to be fused, you must have two complete sentences run together with no punctuation. In the example above, a comma joins the two sentences. La'Mia studied comma splices and fused sentences ... begins one sentence. Finally, she put away her notes ... starts the second sentence.
Thus, this error is a comma splice.
To fix the problem above, you could put a period after burst and begin finally with a capital F.