Chapter 1 $match homework answers don't match

I think I have the correct $match pipeline for the homework but I got 24 instead of 23. Why is there 1 extra? Could there be an entry added sometimes later that screwed up the answer? Also, I don’t understand the list of possible answer in the question. What are those numbers for? No 23 or 24 in the list of answer? Thanks in advance,

It sounds like you’re talking about the M121 Aggregation Framework course. Please relink this thread to that course if so.