M/C can be tricky. Occasionaly they switch a single letter in a word, ie m's into n's or o's into a's. Just make sure to double check.
How I differentiate between Loro as they, which this sentence wants and Loro as you formal plural which was my initial translation?
Loro always means they as ellos always means they in spanish. There is a word for you all formal that uses the same conjugation (like mangiano) but the noun is never loro for you all formal, so in this case the answer is they.
Just wondering why this isn't "il" ciaccolato (simply ciaccolato without the "il" seems wrong, in other words)...
I notice someone else commented the same thing, the sentence I wrote was exactly the same as the answer but yet it was wrong